Asteroids are small Solar System bodies in orbit around the Sun, especially in the inner Solar System; they are smaller than planets but larger than meteoroids. (Source: Wikipedia article "Asteroid.")
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9950 ESA is an Amor asteroid. It orbits the Sun once every 3.81 years.
Discovered on November 8, 1990 by C. Pollas it was given the provisional designation "1990 VB". It was later renamed "ESA" after the European Space Agency.
31 Euphrosyne is one of the largest main-belt asteroids, discovered by James Ferguson on September 1, 1854. It was the first asteroid found from North America. It is named after Euphrosyne, one of the Charites in Greek mythology.
It is a fairly dark body near the belt's outer edge. Consequently Euphrosyne is never visible with binoculars, having a maximum magnitude at the best possible opposition of around +10.2, as in November 2011, which is actually fainter than any of the thirty asteroids previously discovered.
It is a very little-studied body despite being one of the largest asteroids. It is a C-type asteroid with a primitive surface. Its orbit, however, is quite unusual and bears a considerable resemblance to that of 2 Pallas in its high inclination and eccentricity. Whereas Pallas and Eris—the only larger bodies with comparably tilted orbits—have nodes near perihelion and aphelion, Euphrosyne's perihelion lies at the northernmost point of its orbit. During a rare perihelic opposition Euphrosyne is very high in the sky from northern latitudes, but invisible from such countries as New Zealand and Chile.
The mass estimate of Euphrosyne in Baer (2011) makes it apparently the
(48639) 1995 TL8 (also written (48639) 1995 TL8) is a classical Kuiper belt object possessing a relatively large satellite.
The assumed diameter of 352 km is derived from an albedo guess of 0.09, being typical for trans-Neptunian objects.
Discovered in 1995 by Arianna E. Gleason as part of the Spacewatch project, it was the first of the bodies presently classified as a scattered-disc object (SDO) to be discovered, preceding the SDO prototype (15874) 1996 TL66 by almost a year.
A companion was discovered by Denise C. Stephens and Keith S. Noll from observations with the Hubble Space Telescope taken on November 9, 2002, and announced on October 5, 2005. The satellite, designated S/2002 (48639) 1, is relatively large, having a likely mass of about 10% of the primary. Its orbit has not been determined, but it was at a separation of only about 420 km to the primary at the time of discovery, with a possible orbital period of about half a day and an estimated diameter of 161 km.
(48639) 1995 TL8 is classified as scattered–extended by the Deep Ecliptic Survey (DES) since its orbit appears to be beyond significant gravitational interactions with Neptune's current orbit. Though if Neptune
2005 YU55, also written as 2005 YU55, is a potentially hazardous asteroid 310 meters or about 400 m (1,300 feet) in diameter. It was discovered on 28 December 2005 by Robert S. McMillan at Steward Observatory, Kitt Peak. On 8 November 2011 it passed 0.85 lunar distances (324,900 kilometers; 201,900 miles) from the Earth. This is the closest known approach by an asteroid with an absolute magnitude this bright since 2010 XC15 (H = 21.4) approached within 0.5 lunar distances in 1976.
In February 2010, 2005 YU55 was rated 1 on the Torino Scale, indicating that a pass near the Earth poses no unusual level of danger. On 19 April 2010, radar ranging by the Arecibo radio telescope reduced uncertainties about the orbit by 50%. This improvement eliminated any possibility of an impact with the Earth within the next 100 years. It was removed from the Sentry Risk Table on 22 April 2010 and as such it now has a rating of 0 on the Torino Scale.
On 8 November 2011 at 23:28 UT the asteroid passed 0.8453 LD (324,900 km; 201,900 mi) from the Earth. On 9 November 2011 at 07:13 UT the asteroid passed 0.6231 LD (239,500 km; 148,800 mi) from the Moon. During the close approach the asteroid reached about
9968 Serpe (provisional designation: 1992 JS2) is a main belt asteroid. It orbits the Sun once every 4.11 years.
Discovered on May 4, 1992 by H. Debehogne, it was given the provisional designation "1992 JS2".
(145453) 2005 RR43, also written as (145453) 2005 RR43, is a trans-Neptunian object (TNO) estimated to be about 252 km in diameter. It was discovered by Andrew C. Becker, Andrew W. Puckett, and Jeremy Martin Kubica on September 9, 2005 at Apache Point Observatory in Sunspot, New Mexico.
Based on their common pattern of IR water-ice absorptions and neutral visible spectrum, and the clustering of their orbital elements, the KBOs (145453) 2005 RR43, 1995 SM55, (19308) 1996 TO66, (55636) 2002 TX300, and (120178) 2003 OP32 appear to be collisional fragments broken off the dwarf planet Haumea.
The surface is covered by water ice as attested by deep absorption at 1.5 and 2 μm in the infrared spectrum and neutral (i.e. non-red) colour. Scattering models reveal that the observed water ice is, at least in a significant fraction, crystalline and organics, detected on the surface of many TNO, are completely absent. These physical and orbital characteristics common with Haumea led to suggestion that 2005 RR43 is a member of the Haumea collisional family. The object, together with other members of the family ((19308) 1996 TO66, (24835) 1995 SM55, (55636) 2002 TX300, and (120178) 2003 OP32),
2010 TK7 is the first Earth trojan asteroid to be discovered; it precedes Earth in its orbit around the Sun. Trojan objects are most easily conceived as orbiting at a Lagrangian point, a dynamically stable location (where gravitational and centrifugal forces balance) 60 degrees ahead of or behind a massive orbiting body, in a type of 1:1 orbital resonance. In reality, they oscillate (librate) around such a point. Such objects had previously been observed only in the orbits of Mars, Jupiter, Neptune and several moons of Saturn.
2010 TK7 has a diameter of about 300 meters (1,000 ft). Its path oscillates about the Sun–Earth L4 Lagrangian point (60 degrees ahead of Earth), shuttling between its closest approach to Earth and its closest approach to the L3 point (180 degrees from Earth) about every 400 years.
The asteroid was discovered in October 2010 by the NEOWISE team of astronomers using NASA's Wide-field Infrared Survey Explorer (WISE).
WISE, a space telescope launched into Earth orbit in December 2009, imaged 2010 TK7 in October 2010 while carrying out a program to scan the entire sky from January 2010 to February 2011. Spotting an asteroid sharing Earth's orbit is normally
25 Phocaea is a main-belt asteroid. It was discovered by J. Chacornac at Marseille, on April 6. 1853. It was his first asteroid discovery out of a total of six. It is named after Phocaea, the Greek name of Foça in Turkey, from where came the founders of Marseille.
Phocaea has been studied by radar.
9951 Tyrannosaurus is an S-type main belt asteroid. It orbits the Sun once every 3.78 years.
Discovered on November 15, 1990 by E. W. Elst it was given the provisional designation "1990 VK5". On November 21, 2002 it was renamed "Tyrannosaurus" after Tyrannosaurus, a genus of large carnivorous dinosaur of the late Cretaceous.
2007 VK184 is an asteroid which is listed on the Near-Earth Object Risk List with a rating on the Torino Scale of Level 1. A Torino rating of 1 is a routine discovery in which a pass near the Earth is predicted that poses no unusual level of danger. As of 24 June 2011 (2011 -06-24), 2007 VK184 and 2011 AG5 are the only near-earth objects to be listed above Level 0 for potential impacts within 100 years. 2007 VK184 was discovered on November 12, 2007, by the Catalina Sky Survey.
Further observations between December 18, 2007, and January 4, 2008, suggested an increase in the impact probability to 1 in 2700 chance for an impact with Earth during June 2048. A few days later, the impact probability was reverted back to a 1 in 3030 chance.
According to the Near-Earth Object list, 101 observations over 60 days suggests the asteroid has a probability of 1 in 1820 chance of hitting the Earth on June 3, 2048 at a distance of about 0.75 Earth radii (4815km). Those figures translate into a 0.055% chance of hitting (or 99.945% of missing). The nominal close approach is 0.032 AU (4,800,000 km; 3,000,000 mi) on 2048-May-30. The asteroid is estimated to have a diameter of about 130 meters.
2004 HR56 (also written 2004 HR56) is a small Earth-crossing asteroid belonging to the Apollo family and was visible between April 25 to May 10, 2005. This find was documented as part of the FMO Project and was reported by six different observatories. Reports indicate that the object is about 74 metres wide and has an absolute magnitude of 23.28. The object could also be classified as a meteoroid, although the most common definition uses a diameter of 10 m as the demarcation.
40 Harmonia ( /hɑrˈmoʊniə/) is a large main-belt asteroid.
It was discovered by H. Goldschmidt on March 31, 1856, and named after Harmonia, the Greek goddess of harmony. The name was chosen to mark the end of the Crimean War.
Not to be confused with Daphnis (moon).
41 Daphne is a large 174 km main-belt asteroid. This dark-surfaced body is probably composed of primitive carbonaceous chondrites. It was discovered by H. Goldschmidt on May 22, 1856, and named after Daphne, the nymph in Greek mythology who was turned into a laurel tree.
In 1999, Daphne occulted three stars, and on July 2, 1999 produced eleven chords indicating an ellipsoid of 213×160 km. Daphnean lightcurves also suggest that the asteroid is irregular in shape. Daphne was observed by Arecibo radar in April 2008.
41 Daphne has at least one satellite, named S/2008 (41) 1. It was identified on March 28, 2008, and has a projected separation of 443 km, an orbital period of approximately 1.1 days, and an estimated diameter of less than 2 km. If these preliminary observations hold up, this binary system has the most extreme size ratio known.
9986 Hirokun is an S-type main belt asteroid. It orbits the Sun once every 4.12 years.
Discovered on July 12, 1996 by Y. Shimizu and T. Urata, it was given the provisional designation 1996 NX. It was later renamed 9986 Hirokun, after the fiancé of T. Urata's daughter.
38628 Huya is a trans-Neptunian object (TNO). It is a plutino, being in a 2:3 mean motion resonance with Neptune. With an old Spitzer size estimate of 532 ± 25 km, it was a dwarf planet candidate (icy trans-Neptunian objects with a diameter above around 400 km are expected to be spherical) although the IAU has never classified it as such. Light-curve-amplitude analysis, which shows only small deviations, suggests that it is likely a spheroid with small albedo spots. Tancredi (2010) thinks that Huya is very probably a dwarf planet.
It was discovered in March 2000 by Ignacio Ferrin and announced on 24 October 2000. It was assigned the name Huya, after Juyá, the Wayuu rain god, in August 2003 by the International Astronomical Union (IAU).
At the time of its discovery, Huya was the biggest and brightest trans-Neptunian object found since Pluto. It was found using data collected by at the CIDA Observatory in Venezuela.
The Spitzer Space Telescope has estimated Huya to be about 530 km in diameter with a low albedo of around 0.05. The later termination based on a combination of Spitzer and Herschel measurements yielded a smaller size estimate of 438.7+26.5
Huya has a moderately
51 Nemausa ( /nɨˈmɔːzə/) is a large asteroid-belt asteroid similar to 1 Ceres in composition. It was discovered by one "A. Laurent", an obscure figure about whom little is known. Laurent made the discovery from the private observatory of Benjamin Valz in Nîmes, France. The house, at 32 rue Nationale in Nîmes, has a plaque commemorating the discovery. With Laurent's permission, Valz named the asteroid after the Celtic god Nemausus, the patron god of Nîmes during Roman times.
Nemausa measures 147.9km in diameter. Lightcurve data suggests that it may have a small moon. It may have a water content of about 14%. Nemausa has been studied by radar.
90482 Orcus is a trans-Neptunian object in the Kuiper belt with a large moon. It was discovered on February 17, 2004 by Michael Brown of Caltech, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University. Precovery images as early as November 8, 1951 were later identified. It is considered to be a dwarf planet by some astronomers, though the IAU has not formally recognized it as one.
Orcus is a plutino, locked in a 2:3 resonance with Neptune, making two revolutions around the Sun, while Neptune makes three. This is much like Pluto, except that it is constrained to always be in the opposite phase of its orbit from Pluto: Orcus is at aphelion when Pluto is at perihelion and vice versa. Because of this, along with its large moon Vanth that recalls Pluto's large moon Charon, Orcus has been seen as the anti-Pluto. This was a major consideration in selecting its name, as the deity Orcus was the Etruscan equivalent of the Roman Pluto, and later became an alternate name for Pluto.
The surface of Orcus is relatively bright with albedo reaching 30%, grey in color and water rich. The ice is predominantly in crystalline form, which may be related to past cryovolcanic
18 Melpomene is a large, bright main-belt asteroid. It is composed of silicates and metals.
It was discovered by J. R. Hind on June 24, 1852, and named after Melpomenē, the Muse of tragedy in Greek mythology.
Melpomene occulted the star SAO 114159 on December 11, 1978. A possible Melpomenean satellite with a diameter at least 37 km was detected. The satellite candidate received a provisional designation S/1978 (18) 1.
Melpomene was observed with the Hubble Space Telescope in 1993. It was able to resolve the asteroid's slightly elongated shape, but no satellites were detected.
Melpomene has been studied by radar.
59 Elpis ( /ˈɛlpɨs/ EL-pis) is a very large main belt asteroid. It is a C-type asteroid, meaning that it is very dark and carbonaceous in composition.
Elpis was discovered by Jean Chacornac from Paris, on September 12, 1860. It was Chacornac's sixth and final asteroid discovery.
A controversy arose over the naming of Elpis. Urbain Leverrier, director of the Paris Observatory, at first refused to allow Chacornac to name the object, because Leverrier was promoting a plan to reorganize asteroid nomenclature by naming them after their discoverers, rather than mythological figures. A protest arose among astronomers. At the Vienna Observatory, Edmund Weiss, who had been studying the asteroid, asked the observatory's director, Karl L. Littrow, to name it. Littrow chose Elpis, a Greek personification of hope, in reference to the favorable political conditions in Europe at the time. In 1862, Leverrier permitted Chacornac to choose a name, and he selected "Olympia". However, Elpis is the name that stuck.
Elpis has been studied by radar.
(101955) 1999 RQ36 is an Apollo asteroid discovered by LINEAR on September 11, 1999. The asteroid is the planned target of the OSIRIS-REx mission which will return samples to Earth for further study. It is a potential Earth impactor and is listed on the Sentry Risk Table.
It has a mean diameter of approximately 493 meters and has been observed extensively with the Arecibo Observatory Planetary Radar and the Goldstone Deep Space Network.
A recent dynamical study by Andrea Milani and collaborators has located a series of eight potential Earth impacts between 2169 and 2199. The cumulative probability of impact is dependent on poorly known physical properties of the object, but is not higher than 0.07% for all eight encounters. To accurately assess 1999 RQ36's probability of Earth impact will require a detailed shape model of the asteroid and additional observations (either from the ground or from spacecraft visiting the object) to determine the magnitude of the Yarkovsky acceleration.
Separately, 1999 RQ36 has been considered many times as the target of spacecraft missions, including OSIRIS-REx, due to the low Δv required to reach it from Earth orbit. NASA announced on May 25, 2011,
596 Scheila is a main-belt asteroid and main-belt comet orbiting the Sun. It was discovered on 21 February 1906 by August Kopff from Heidelberg. Kopff named the asteroid after a female English student with whom he was acquainted.
On December 11.4 2010, Steve Larson of the Catalina Sky Survey detected a comet-like appearance to asteroid Scheila: it displayed a "coma" of about magnitude 13.5. Inspection of archival Catalina Sky Survey observations showed the activity was triggered between 2010 November 11 and December 3. Imaging with the 2-meter Faulkes Telescope North revealed a linear tail in the anti-sunward direction and an orbital tail, indicative of larger slower particles.
When first detected it was unknown what drove the ejecta plumes. Scheila's gravity is too large for electrostatics to launch dust. Cometary outgassing could not be ruled out until detailed spectroscopic observations indicated the absence of gas in Scheila's plumes. Observations by the Hubble Space Telescope and the Swift Gamma Ray Burst Mission's UV-optical telescope make it most likely that Scheila was impacted at ~5 km/s by a previously unknown asteroid ~35 meters in diameter. In 2010, the Hubble Space
65 Cybele is one of the largest asteroids in the Solar System and is located in the outer asteroid belt. It gives its name to the Cybele family of asteroids that orbit outward from the Sun from the 2:1 orbital resonance with Jupiter. Cybele is a C-type asteroid, meaning that it is dark in color and carbonaceous in composition. It was discovered in 1861 by Ernst Tempel and named after Cybele the earth goddess.
Cybele was discovered on March 8, 1861, by Ernst Tempel from the Marseilles Observatory. A minor controversy arose from its naming process. Tempel had awarded the honour of naming the asteroid to Carl August von Steinheil in recognition of his achievements in telescope production. Von Steinheil elected to name it "Maximiliana" after the reigning monarch Maximilian II of Bavaria. At the time, asteroids were conventionally given classical names, and a number of astronomers protested this contemporary appellation. The name Cybele was chosen instead, referring to the Phrygian goddess of the earth.
The first Cybelian stellar occultation was observed on October 17, 1979 in the Soviet Union. The asteroid appeared to have an irregular shape, with the longest chord being measured as
68 Leto ( /ˈliːtoʊ/ LEE-toh; Greek: Λητώ) is a large main belt asteroid. Its spectral type is S. It was discovered by Robert Luther on April 29, 1861. The asteroid is named after Leto, the mother of Apollo and Artemis in Greek mythology.
23 Thalia is a large main-belt asteroid. It was discovered by J. R. Hind on December 15, 1852, at the private observatory of W. Bishop, located in Hyde Park, London, England. Bishop named it after Thalia, the Muse of comedy and pastoral poetry in Greek mythology.
It is categorized as an S-type asteroid consisting of mainly of iron- and magnesium-silicates. This the second most common type of asteroid in the main belt. Based on analysis of the light curve, the object has a sidereal rotation period of 0.513202 ± 0.000002 days. An ellipsoidal model of the light curve gives an /b ratio of 1.28 ± 0.05.
With a semimajor axis of 2.628, the asteroid is orbiting between the 3:1 and 5:2 Kirkwood gaps in the main belt. Its orbital eccentricity is larger than the median value of 0.07 for the main belt, and the inclination is larger than the median of below 4°. But most of the main-belt asteroids have an eccentricity of no more than 0.4 and an inclination of up to 30°, so the orbit of 23 Thalia is not unusual for a main-belt asteroid.
Thalia has been studied by radar.
54411 Bobestelle is an asteroid discovered June 3, 2000 by Peter B. Stetson and David D. Balam at the Canada-France-Hawaii Telescope at Mauna Kea. Its provisional designation was 2000 LH10.
Peter Stetson, who discovered the asteroid, is an astronomer with the National Research Council of Canada's Dominion Astrophysical Observatory (DAO). David Balam of the University of Victoria (UVic) confirmed the discovery and performed follow-up observations.
7 Iris is a large main-belt asteroid. Among the S-type asteroids, it ranks fifth in geometric mean diameter after Eunomia, Juno, Amphitrite and Herculina.
Its bright surface and small distance from the Sun make Iris the fourth brightest object in the asteroid belt after Vesta, Ceres, and Pallas. But at typical oppositions it marginally outshines the larger though darker Pallas. It has a mean opposition magnitude of +7.8, comparable to that of Neptune, and can easily be seen with binoculars at most oppositions. At rare oppositions near perihelion Iris can reach a magnitude of +6.7 (next time on October 31, 2017 reaching a magnitude of +6.9), which is as bright as Ceres ever gets; reports of it being seen without optical aid are unverified.
It was the seventh asteroid discovered, on August 13, 1847, by J. R. Hind from London, UK. It was Hind's first asteroid discovery.
Iris was named after the rainbow goddess Iris of Greek mythology, sister of the Harpies and messenger of the gods, especially Hera. Her quality of attendant of Hera was particularly appropriate to the circumstances of discovery, as she was spotted following 3 Juno (Juno is the Roman equivalent of Hera) by less than an
9967 Awanoyumi is a main belt asteroid. It orbits the Sun once every 4.16 years.
Discovered on March 31, 1992 by K. Endate and K. Watanabe, it was given the provisional designation "1992 FV1". It was later renamed Awanoyumi after Yumi Awano, the curator of the Okayama Astronomical Museum.
9983 Rickfienberg is a main belt asteroid. It orbits the Sun once every 4.45 years.
Discovered on February 19, 1995 by Dennis di Cicco, it was given the provisional designation 1995 DA. It was later renamed 9983 Rickfienberg after Richard Tresch Fienberg, the editor of Sky & Telescope at the time.
216 Kleopatra ( /ˌkliːɵˈpætrə/) is a main-belt asteroid. It was discovered by Johann Palisa on April 10, 1880, from Pula. It is named after Cleopatra, the famous queen of Ancient Egypt. It is notable for its peculiar bilobate shape, which has been compared to a dog's bone. It was recently discovered to be a ternary asteroid, having two small moons.
Kleopatra is a relatively large asteroid, measuring 217 × 94 × 81 km. Calculations from its radar albedo and the orbits of its moons show it to be a rubble pile, a loose amalgam of metal, rock, and 30–50% empty space by volume, likely due to a disruptive impact prior to the impact that created its moons.
Kleopatra has an unusual shape that has been compared to a dog's bone. This bilobate shape was revealed by adaptive optics on the ESO 3.6 m Telescope at La Silla, run by the European Southern Observatory. By bouncing radar signals off the asteroid, a team of astronomers at the Arecibo radio telescope in Puerto Rico were able to develop a more detailed computer model of its shape, which confirmed the earlier results.
In September 2008, Franck Marchis and his collaborators announced that by using the Keck Observatory's adaptive optics
4183 Cuno is an Apollo, Mars- and Venus-crosser asteroid. It was discovered in 1959 by Cuno Hoffmeister, from whom the asteroid takes its name.
Cuno is about 4–9 km in diameter and is an S-type asteroid, meaning that it is highly reflective and composed of nickel-iron mixed with iron- and magnesium-silicates.
In December 2000, Cuno was analysed by radar to determine its shape. The resultant images are lacking in detail, but indicate a rough sphere with some kind of concave depression 1–2 km in diameter.
4183 Cuno approaches the Earth to within 40 Gm six times in the 21st century. On 2012-May-20 Cuno made its closest Earth approach at a distance of 0.12182 AU (18,224,000 km; 11,324,000 mi). It will not make a closer approach until 2093.
433 Eros is a near-Earth asteroid (NEA) discovered in 1898, and the first asteroid to be orbited by a probe (in 2000). It is an S-type asteroid approximately 34.4×11.2×11.2 km in size, the second-largest NEA after 1036 Ganymed, and belongs to the Amor group.
Eros is a Mars-crosser asteroid, the first known to come within the orbit of Mars. Objects in such an orbit can remain there for only a few hundred million years before the orbit is perturbed by gravitational interactions. Dynamical integrations suggest that Eros may evolve into an Earth-crosser within as short an interval as 2 million years, and has a roughly 50% chance of doing so over a time scale of 10–10 years. It is a potential Earth impactor, comparable in size to the impactor that created the Chicxulub Crater and led to the extinction of the dinosaurs.
The NEAR Shoemaker probe visited Eros twice, first with a 1998 flyby, and then by orbiting it in 2000 when it extensively photographed its surface. On February 12, 2001, at the end of its mission, it landed on the asteroid's surface using its maneuvering jets.
Eros is named after the Greek god of love, Erōs. It is pronounced /ˈɪərɒs/ EER-os or sometimes /ˈɛrɒs/ ERR-os.
1338 Duponta (1934 XA) is a main-belt asteroid discovered on December 4, 1934 by Boyer, L. at Algiers. Since the albedo of this asteroid is unknown, the size can only be estimated as between about 8 km - 19 km, based on the absolute magnitude (H) of 12.3.
Photometric observations in 2007 revealed a ~3 km satellite (diameter ratio of 0.23) with an orbital period of 17.57 hours. Due to the similar size of the primary and secondary the Minor Planet Center lists this as a binary companion.
142 Polana is a very dark main belt asteroid. It was discovered by Johann Palisa on January 28, 1875, and named after the city of Pola (now Pula, Croatia), home of the Austrian Naval Observatory where he made the discovery.
It is a major member of the eponymously-named Polana family, which is a subgroup of the Nysa family. The asteroid has an estimated diameter of about 55.3 km and a low albedo of 0.045. It is orbiting at a distance of 2.419 times the separation of the Earth from the Sun, with an orbital period of 3.76 years and an eccentricity of 0.14.
In the Tholen classification scheme, Polana is a primitive carbonaceous asteroid of type F, which is a subdivision of more common C-type. Under the SMASS classification taxonomy, Polana is listed as a B-type asteroid; a group that combines both the Tholen B and F types. The spectrum of this object suggests the presence of magnetite (Fe3O4), which gives it the spectrally-blue coloration that is a characteristic of this SMASS class.
Polana is in a 1:2 orbital resonance with Mars, meaning that Polana orbits the Sun once for every two orbits that Mars completes. This resonance helps protect the asteroid from orbital erosion: the orbital
132524 APL (previously known by its provisional designation, 2002 JF56) is a small asteroid about 2.3 kilometers across visited by the New Horizons probe, which passed it at about 101,867 km at 04:05 UTC on June 13, 2006. The spectra obtained by New Horizons shows that APL is an S-type asteroid.
Alan Stern, principal investigator for New Horizons, named the asteroid in reference to the Johns Hopkins Applied Physics Lab, which runs the mission.
9974 Brody is a main belt asteroid. It orbits the Sun once every 3.70 years.
Discovered on July 19, 1993 by E. W. Elst, it was given the provisional designation 1993 OG13. It was later renamed "Brody" after Adrien Brody, who portrayed the character Wladyslaw Szpilman in The Pianist.
(136617) 1994 CC is a near-Earth asteroid that was discovered on February 3, 1994, by Spacewatch's Jim Scotti. In June 2009 it was shown to be a triple system, i.e. the main body has two satellites; only about one percent (1%) of near-Earth asteroids observed by a radar are found to be triple systems such as this one.
A team of NASA's Jet Propulsion Laboratory (JPL) (Pasadena, California) scientists led by Marina Brozovic and Lance Benner, made the discovery using radar imaging at NASA's Goldstone Solar System Radar on June 12 and June 14, 2009. They showed that the near-Earth asteroid 1994 CC is a triple system, which encountered Earth within 2.52 million kilometers on June 10, 2009. This relatively close approach to Earth made the discovery possible, as before the approach, scientists knew very little about this asteroid. In fact, 1994 CC is only the second triple system known in the near-Earth objects population.
1994 CC consists of a central object about 700 meters in diameter that has two moons revolving around it. Scientists' preliminary analysis of the system suggests that the moons are at least 50 meters in diameter. In a similar study, the radar observations at Arecibo
4179 Toutatis/1989 AC ( /tuːˈtɑːtɨs/ too-TAH-tis) is an Apollo, Alinda, and Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with the planet Jupiter, a 1:4 resonance with the planet Earth, and frequent close approaches to the terrestrial planets, including Earth. It is listed as a potentially hazardous object, although the odds of a collision with the Earth are very small.
4179 Toutatis was first sighted on February 10, 1934, as object 1934 CT, and then promptly lost. It remained a lost asteroid for several decades until it was recovered on January 4, 1989, by Christian Pollas, and was named after the Celtic god Toutatis/Teutates—known to popular culture as the God that the cartoon character Astérix's chief Vitalstatistix evokes so that the sky may never fall on his head.
The spectral properties suggest that this is an S-type, or stony asteroid, consisting primarily of silicates. It has a moderately bright Bond albedo of 0.13. Radar imagery shows that Toutatis is a highly irregular body consisting of two distinct "lobes", with maximum widths of about 4.6 km and 2.4 km respectively. It is hypothesized that Toutatis formed from two originally separate bodies
9988 Erictemplebell is a main belt asteroid. It orbits the Sun once every 4.94 years.
Discovered on September 9, 1997 by Paul G. Comba, it was given the provisional designation 1997 RX6. It was later renamed 9988 Erictemplebell in honour of Eric Temple Bell, a professor at the California Institute of Technology where he taught a class on algebra which the discoverer took.
57 Mnemosyne ( /nɨˈmɒsɨniː/ ni-MOS-i-nee) is a large main belt asteroid. It is an S-type asteroid in composition. It was discovered by Robert Luther on September 22, 1859 from Düsseldorf. Its name was chosen by Martin Hoek, director of the Utrecht Observatory, in reference to Mnemosyne, a Titaness in Greek mythology.
12 Victoria is a large main-belt asteroid.
It was discovered by J. R. Hind on September 13, 1850.
Victoria is officially named after the Roman goddess of victory, but the name also honours Queen Victoria. The goddess Victoria (Nike for the Greeks) was the daughter of Styx by the Titan Pallas. The coincidence with the name of the then-reigning queen caused quite a controversy at the time, and B. A. Gould, editor of the prestigious Astronomical Journal, adopted the alternate name Clio (now used by 84 Klio), proposed by the discoverer. However, W. C. Bond, of the Harvard College Observatory, then the highest authority on astronomy in America, held that the mythological condition was fulfilled and the name therefore acceptable, and his opinion eventually prevailed.
Radar and speckle interferometry observations show that the shape of Victoria is elongated, and it is suspected to be a binary asteroid.
Victoria has only ever been observed to occult a star thrice since its discovery.
46 Hestia ( /ˈhɛstiə/) is a large, dark main-belt asteroid. It is also the primary body of the Hestia clump, a group of asteroids with similar orbits.
Hestia was discovered by N. R. Pogson on August 16, 1857, at the Radcliffe Observatory, Oxford. Pogson awarded the honour of naming it to William Henry Smyth, the previous owner of the telescope used for the discovery. Smyth chose to name it after Hestia, Greek goddess of the hearth. This created a problem in Greek, where 4 Vesta also goes by the name Hestia.
Hestia has been studied by radar.
In 2000, Michalak estimated Hestia to have a mass of 3.5×10 kg.
Even though Hestia is only about 124 km in diameter, in 1997, Bange and Bec-Borsenberger estimated Hestia as having a mass of 2.1×10 kg, based on a perturbation by 19 Fortuna. This older 1997 estimate would give it a density of 14+ g/cm³ and make Hestia more massive than several much larger asteroids.
10001 Palermo is a main-belt asteroid. Discovered on October 8, 1969, it was named "Palermo" after Palermo, the capital of Sicily where Giuseppe Piazzi made the first discovery of an asteroid, 1 Ceres. The naming was made in January 2001 to honour the discovery of Ceres, as that was the 200th anniversary of that discovery.
The asteroid is about six kilometers in radius, although it may be irregularly shaped. It orbits the Sun every 3.67 years.
704 Interamnia is a very large asteroid, with an estimated diameter of 350 kilometres. Its mean distance from the Sun is 3.067 (AU). It was discovered on October 2, 1910 by Vincenzo Cerulli, and named after the Latin name for Teramo, Italy, where Cerulli worked. It is probably the fifth-most-massive asteroid after Ceres, Vesta, Pallas, and Hygiea, with a mass estimated to be 1.2% of the mass of the entire asteroid belt.
Although Interamnia is the largest asteroid after the "big four", it is a very little-studied body. It is easily the largest of the F-type asteroids, but there exist very few details of its internal composition or shape, and no lightcurve analysis has yet been done to determine the ecliptic coordinates of Interamnia's poles (and hence its axial tilt). Its apparently high bulk density (though subject to much error) suggests an extremely solid body entirely without internal porosity or traces of water. This also strongly suggests that Interamnia is large enough to have fully withstood all the collisions that have occurred in the asteroid belt since the Solar System was formed.
Its very dark surface and relatively large distance from the Sun means Interamnia can never
87 Sylvia is one of the largest main-belt asteroids. It is a member of the Cybele group located beyond the core of the belt (see minor-planet groups). Sylvia is remarkable for being the first asteroid known to possess more than one moon.
Sylvia was discovered by N. R. Pogson on May 16, 1866 from Madras (Chennai), India. A. Paluzie-Borrell, writing in Paul Erget's The Names of the Minor Planets (1955), mistakenly states that the name honours Sylvie Petiaux-Hugo Flammarion, the first wife of astronomer Camille Flammarion. In fact, in the article announcing the discovery of the asteroid, Pogson explained that he selected the name in reference to Rhea Silvia, mother of Romulus and Remus (MNRAS, 1866).
Sylvia is very dark in color and probably has a very primitive composition. The discovery of its moons made possible an accurate measurement of the asteroid's mass and density. Its density was found to be very low (around 1.2 times the density of water), indicating that the asteroid is porous to very porous; from 25% to as much as 60% of it may be empty space, depending on the details of its composition. However, the mineralogy of the X-type asteroids is not known well enough to constrain
9999 Wiles is a C-type main belt asteroid. It orbits the Sun every 4.8 years.
It was discovered by C. J. van Houten, I. van Houten-Groeneveld and T. Gehrels on September 29, 1973. Given the provisional designation 4196 T-2, it was renamed 9999 Wiles in honour of Andrew J. Wiles, who proved Fermat's last theorem.
3552 Don Quixote is a small Amor, Mars-crossing, Jupiter-crossing, potentially hazardous asteroid. It has a highly inclined comet-like orbit, and measures about 19 km in diameter. Its rotation period is 7.7 hours. It was discovered by Paul Wild in 1983, and is named after the comic knight who is the eponymous hero of Cervantes' Spanish novel Don Quixote (1605).
Don Quixote is suspected to be an extinct comet. Don Quixote is frequently perturbed by Jupiter.
67 Asia ( /ˈeɪʃiə/ AY-shee-ə) is a bright asteroid from the asteroid belt. It was discovered by N.R. Pogson on April 17, 1861, from the Madras Observatory.
Pogson chose the name to refer both to Asia, a Titaness in Greek mythology, and to the continent of Asia, because the asteroid was the first to be discovered from that continent.
9984 Gregbryant is a main belt asteroid. It orbits the Sun once every 3.93 years.
Discovered by R. H. McNaught and J. B. Child on April 18, 1996 it was given the provisional designation 1996 HT. It was later renamed 9984 Gregbryant after Greg Bryant, the editor of the Astronomical Society of New South Wales' journal.
944 Hidalgo ( /hɨˈdælɡoʊ/ hi-DAL-goh) is a small Solar System body with a semi-major axis beyond Jupiter's and an orbital period of 13.77 years. This makes it a centaur, but it was discovered in 1920 and has hence traditionally been considered an asteroid.
944 Hidalgo is a centaur because it has a semi-major axis between Jupiter's and Neptune's. Despite this, the Minor Planet Center (MPC) does not list it as a centaur. Hidalgo has traditionally been considered an asteroid because it was discovered long before the identification of centaurs as a distinct class.
With a high eccentricity of 0.66, its perihelion of 1.95 AU takes it to the inner edge of the asteroid belt, while its aphelion of 9.54 AU takes it right out to Saturn's orbit, a characteristic normally associated with Saturn's family of comets. Some astronomers therefore suspect that it was once a comet. Strictly speaking, Hidalgo is a Saturn-grazer rather than a Saturn-crosser as its aphelion does not clear Saturn's. Hidalgo's severe orbital inclination of 43° is suspected to be the result of a close encounter with Jupiter. Even as recently as 1922, Hidalgo passed within 0.89AU of the powerful influence of Jupiter. Its
(84922) 2003 VS2 is a trans-Neptunian object discovered by the Near Earth Asteroid Tracking program on November 14, 2003. Like Pluto, it is in a 2:3 orbital resonance with Neptune, giving it the orbital properties of a plutino. Mike Brown's website lists it as highly likely a dwarf planet. However Brown assumed that VS2 is much bigger than it really is and the light-curve analysis has questioned whether it would truly be in the hydrostatic equilibrium.
Like Pluto, 2003 VS2 is locked in the 3:2 mean motion resonance with Neptune, although its orbit is significantly less eccentric less than Pluto's is. It also has slightly smaller orbital inclination.
2003 VS2 has a significant light-curve amplitude of 0.21 ± 0.01. The most likely value of the rotation period is 7.41 ± 0.02 hours.
2003 VS2 has a moderately red surface with a moderately red color indexes B-V=0.93, V-R=0.59. The geometrical albedo is about 15%.
In 2007 its diameter was initially estimated by Spitzer Space Telescope at 725 ± 200 km. However in 2012 this was reduced to 523.0+35.1
−34.4 km after new Herschel Space Telescope observations. The latter measurement is considered more reliable. Assuming a Pluto like density of
2007 WD5 is a 50 m (160 ft) diameter Apollo class near-Earth object and a Mars-crosser asteroid discovered on November 20, 2007, by Andrea Boattini of the Catalina Sky Survey. Early observations of 2007 WD5 caused excitement amongst the scientific community when it was estimated as having as high as a 1 in 25 chance of colliding with Mars on January 30, 2008. However, by January 9, 2008, additional observations allowed NASA's Near Earth Object Program (NEOP) to reduce the uncertainty region resulting in only a 1-in-10,000 chance of impact. 2007 WD5 most likely passed Mars at a distance of 6.5 Mars radii. Due to this relatively small distance and the uncertainty level of the prior observations, the gravitational effects of Mars on its trajectory are unknown and, according to Steven Chesley of NASA's Jet Propulsion Laboratory Near-Earth Object program, 2007 WD5 is currently considered 'lost' (see lost asteroids).
The asteroid was discovered on November 20, 2007 by Andrea Boattini of the NASA-funded Catalina Sky Survey on Mount Lemmon, near Tucson, Arizona, USA, using a 1.5m telescope. It was discovered in the constellation Taurus at an apparent magnitude of +20. This is about 400,000
253 Mathilde ( /məˈtɪldə/) is a main-belt asteroid about 50 km in diameter that was discovered by Johann Palisa in 1885. It has a relatively elliptical orbit that requires more than four years to circle the Sun. This asteroid has an unusually slow rate of rotation, requiring 17.4 days to complete a 360° revolution about its axis. It is a primitive C-type asteroid, which means the surface has a high proportion of carbon; giving it a dark surface that reflects only 4% of the light that falls on it.
This asteroid was visited by the NEAR Shoemaker spacecraft during June 1997, on its way to asteroid 433 Eros. During the flyby, the spacecraft imaged a hemisphere of the asteroid, revealing many large craters that have gouged out depressions in the surface. Until 21 Lutetia was visited in 2010, it was the largest asteroid to be visited by a spacecraft and the first C-type asteroid to be explored.
In 1880, Johann Palisa, the director of the Austrian Naval Observatory, was offered a position as an assistant at the newly completed Vienna Observatory. Although the job represented a demotion for Johann, it gave him access to the new 27-inch (690 mm) refractor, the largest telescope in the world
9965 GNU is a C-type main belt asteroid. It orbits the Sun once every 3.76 years.
Discovered on March 5, 1992 by Spacewatch, it was given the provisional designation "1992 EF2". It was later renamed "GNU" after the GNU project.
Other free-software-related asteroid names:
Asteroid 15017 Cuppy, a main-belt object previously known as 1998 SS25, was discovered on September 22, 1998, by Edward L. G. Bowell of the Lowell Observatory Near-Earth-Object Search (LONEOS), Anderson Mesa Station. It was named in September 2003 for Will Cuppy (1884–1949), American humorist and journalist.
5535 Annefrank /ˌæn ˈfræŋk/ is an inner main-belt asteroid, and member of the Augusta family. It was discovered by Karl Reinmuth in 1942. It is named after Anne Frank, the Dutch-Jewish diarist who died in a concentration camp (the name was not chosen until about 1995). The asteroid was used as a target to practice the flyby technique that the Stardust space probe would later use on the comet Wild 2.
Annefrank orbits among the main-belt asteroids, with its shortest axis aligned roughly normal to its orbital plane.
On November 2, 2002, the Stardust space probe flew past Annefrank at a distance of 3079 km. Its images show the asteroid to be 6.6 × 5.0 × 3.4 km, twice as big as previously thought, shaped like a triangular prism, with several visible impact craters. From the photographs, the albedo of Annefrank was computed to be between 0.18 and 0.24. Preliminary analysis of the Stardust imagery suggests that Annefrank may be a contact binary, although other possible explanations exist for its observed shape.
Later ground based lightcurve data was used in an attempt to measure Annefrank's rotational period. Their data resulted in possible rotational periods of 0.5, 0.63 or 0.95 days,
22 Kalliope is a large main belt M-type asteroid discovered by J. R. Hind on November 16, 1852. It is named after Calliope, the Greek Muse of epic poetry. It is orbited by a small moon named Linus.
Kalliope is somewhat elongated, approximately 166 km in diameter, and slightly asymmetric, as evidenced by resolved images taken with the VLT at the European Southern Observatory. This new diameter, which was measured by observing mutual eclipses of Kalliope and Linus, is smaller by 8% than that determined by the IRAS satellite in 1980s.
The spectrum of Kalliope is an M-type, indicating that its surface may be partially composed of iron–nickel metal. The asteroid's density is about 3.4 g/cm. Since the asteroid is likely to be a rubble pile, accounting for a possible porosity of 20–40% leads to the material density of 4.2–5.8 g/cm, which means that Kalliope is probably made of a mixture of metal with silicates. Spectroscopic studies have shown, however, evidence of hydrated minerals and silicates, which indicate rather a stony surface composition. Kalliope also has a low radar albedo, which is inconsistent with a purely metallic surface.
Lightcurve analysis indicates that Kalliope's pole
(52760) 1998 ML14 (also written (52760) 1998 ML14) is an as yet unnamed near-Earth and Mars-crosser asteroid. It was discovered by LINEAR in 1998. It is approximately 1.5 km in diameter.
Shortly after its discovery, 1998 ML14 was imaged by radar at Goldstone and Arecibo. The study showed that the asteroid has a rotation period of 15 hours, and a shape that is roughly spherical, with some steep protrusions and large craters.
11 Parthenope is a large, bright main-belt asteroid.
Parthenope was discovered by Annibale de Gasparis on May 11, 1850, the second of his nine asteroid discoveries. It was named after Parthenopē, one of the Sirens in Greek mythology, said to have founded the city of Naples. De Gasparis "used his utmost endeavours to realise a 'Parthenope' in the heavens, such being the name suggested by Sir John Herschel on the occasion of the discovery of Hygeia in 1849".
There have been two observed Parthenopian occultations, on February 13, 1987, and April 28, 2006.
On August 6, 2008, during a perihelic opposition, Parthenope had an apparent magnitude of 8.8.
In 2007, Baer and Chesley calculated a higher mass and density for Parthenope based on perturbations by the 90 km asteroid 17 Thetis. Baer and Chesley calculated a mass of 6.3×10 kg with a density of 3.3 g/cm³. 2008 estimates by Baer suggest a mass of 6.15×10. The 1997 and 2001 estimates by Viateau and Rapaport were closer to 5×10 kg with a density of 2.7 g/cm³.
15779 Scottroberts is a main belt asteroid. Discovered on July 26, 1993 by Carolyn S. Shoemaker and David H. Levy at Palomar Observatory with the 18" Schmidt Camera, it was originally designated 1993 OA3. Also known as a minor planet or planetoid, 1993 OA3 was renamed by the discoverers for Scott W. Roberts (born 1959), who for many years has encouraged amateur astronomers to pursue their love of the night sky, spending much time teaching people how to use and enjoy their telescopes.
16 Psyche is one of the ten most massive main-belt asteroids. It is over 200 kilometers in diameter and contains a little less than 1% of the mass of the entire asteroid belt. It is the most massive metallic M-type asteroid.
Psyche was discovered by Annibale de Gasparis on March 17, 1852 from Naples and named after the Greek mythological figure Psyche. The first fifteen asteroids to be discovered were given symbols by astronomers as a type of short-hand notation. In 1851, however, J. F. Encke suggested using a circled number. 16 Psyche was the first new asteroid to be discovered that was designated with this scheme (in 1852 by J. Ferguson).
Radar observations indicate a fairly pure iron–nickel composition. Psyche appears to be a genuine case of an exposed metallic core from a larger differentiated parent body. Unlike some other M-type asteroids, Psyche shows no sign of the presence of water or water-bearing minerals on its surface, consistent with its interpretation as a metallic body. Small amounts of pyroxene appear to be present.
If Psyche is the core remnant of a larger parent body, we might expect other asteroids on similar orbits. Psyche does not belong to any asteroid
9975 Takimotokoso is a main belt asteroid. It orbits the Sun once every 3.86 years.
Discovered on September 12, 1993 by K. Endate and K. Watanabe it was given the provisional designation 1993 RZ1. It was later renamed Takimotokoso after Koso Takimoto, the associate president of the Hiroshima Astronomical Society.
1221 Amor is the namesake of the Amor asteroids, a group of near-Earth asteroids whose orbits range between those of Earth and Mars. Amors are often Mars-crossers but they are not Earth-crossers.
Eugène Joseph Delporte photographed Amor as it approached Earth to within 16 million kilometers (about 40 times the distance from Earth to the moon); this was the first time that an asteroid was seen to approach Earth so closely. A month later, 1862 Apollo was seen to cross Earth's orbit, and the scientific community suddenly realised the potential threat these flying mountains presented.
Amor is named after the Roman god of love, better known as Cupid. See also 763 Cupido and 433 Eros, which is named after Cupid's Greek counterpart. Coincidentally, 433 Eros, like 1221 Amor, makes close approaches to Earth. It is a Mars-crosser as well.
53 Kalypso ( /kəˈlɪpsoʊ/) is a large and very dark main belt asteroid. It was discovered by Robert Luther on April 4, 1858 at Düsseldorf. It is named after Calypso, a sea nymph in Greek mythology, a name it shares with Calypso, a moon of Saturn.
Kalypso has been studied by radar.
63 Ausonia ( /ɔːˈsoʊniə/ aw-SOH-nee-ə) is a large main belt asteroid. It was discovered by Annibale de Gasparis on February 10, 1861 from the Astronomical Observatory of Capodimonte, Naples. The initial choice of name for the asteroid was "Italia", after Italy, but this was modified to Ausonia, an ancient classical name for the Italian region.
Based on its lightcurve, a small moon has been suggested.
69 Hesperia ( /hɛsˈpɪəriə/ hes-PEER-ee-ə) is a large, M-type main-belt asteroid. It was discovered by the famous Italian astronomer Giovanni Schiaparelli on April 26, 1861 from Milan. It was his only asteroid discovery. Schiaparelli named it Hesperia in honour of Italy (the word is a Greek term for the peninsula).
Hesperia was observed by Arecibo radar in February 2010. Radar observations combined with lightcurve-based shape models, lead to a diameter estimate of 110 ± 15 km.
Vesta, formally designated 4 Vesta, is one of the largest asteroids in the Solar System, with a mean diameter of about 525 kilometres (326 mi). It was discovered by Heinrich Wilhelm Olbers on 29 March 1807, and is named after Vesta, the virgin goddess of home and hearth from Roman mythology.
Vesta is the second-most-massive asteroid after the dwarf planet Ceres, and comprises an estimated 9% of the mass of the asteroid belt. The less-massive Pallas is slightly larger, making Vesta third in size. Vesta is the last remaining rocky protoplanet (with a differentiated interior) of the kind that formed the terrestrial planets. It lost some 1% of its mass less than a billion years ago in a collision that left an enormous crater occupying much of its southern hemisphere. Debris from this event has fallen to Earth as howardite–eucrite–diogenite (HED) meteorites, a rich source of information about the asteroid.
Vesta is the brightest asteroid visible from Earth. Its maximum distance from the Sun is slightly farther than the minimum distance of Ceres from the Sun, though its orbit lies entirely within the Cererian orbit.
NASA's Dawn spacecraft entered orbit around Vesta on 16 July 2011 for a
(55565) 2002 AW197 is a classical Kuiper belt object (cubewano). Measurements with the Spitzer Space Telescope have confirmed 2002 AW197 as a reliable dwarf-planet candidate, although it has not been officially classified as such by the IAU. Light-curve-amplitude analysis shows only small deviations, which suggests that 2002 AW197 is a spheroid with small albedo spots. Tancredi (2010) accepts it as a dwarf planet. Mike Brown's website lists it as a highly likely dwarf planet.
It was discovered on January 10, 2002, by Michael E. Brown et al. It is located near the Kuiper cliff.
Observations of thermal emissions by the Spitzer Space Telescope in 2007 give a diameter of 734+116
−108 km and an albedo of 0.117+.04
−.03. The lower size estimate for a dwarf planet is about 400 km.
ESO analysis of spectra reveals a strong red slope and no presence of water ice (in contrast to Quaoar, also red) suggesting organic material (see comparison of colours and typical composition inferred from spectra of the TNOs).
It is currently 46.2 AU from the Sun. It will come to perihelion around 2079.
1036 Ganymed is the largest Amor asteroid, at about 32 km in diameter. It was discovered by Walter Baade on October 23, 1924. It has a very well determined orbit, and its next pass of the Earth will be at a distance of 0.374097 AU (55,964,100 km; 34,774,500 mi) on 13 October 2024. It is also a Mars-crosser asteroid, and will pass 0.02868 AU (4,290,000 km; 2,666,000 mi) from Mars on 16 December 2176.
Ganymed is the German spelling of Ganymede, the Trojan prince turned god whom Zeus designated the cupbearer to the Greek gods. Jupiter's moon Ganymede is named after the same, but uses the English spelling.
Owing to its early discovery date, Ganymed has a rich observational history. A 1931 paper published the absolute magnitude, based on observations to date, as 9.24, slightly brighter than the present value of 9.45. Ganymed is an S-type asteroid, meaning that it is relatively reflective and composed of iron and magnesium silicates. Spectral measurements put Ganymed in the S (VI) spectral subtype, indicating a surface rich in orthopyroxenes, and possibly metals (although if metals are present they are covered and not readily apparent in the spectra).
In 1998, radar observations of
2004 XP14 (also written 2004 XP14) is a near-Earth asteroid, first discovered on December 10, 2004, by the LINEAR project.
Due to the proximity of its orbit to Earth and its estimated size, this object has been classified as a "Potentially Hazardous Asteroid" (PHA) by the Minor Planet Center in Cambridge, Massachusetts. Although initially there were concerns that it might possibly impact Earth later in the 21st century and thus merit special monitoring, further analysis of its orbit has since ruled out any such collision, at least in the foreseeable future.
The size of 2004 XP14 is not precisely known. Based on optical measurements, the object is between 300 and 900 meters in diameter.
2004 XP14's closest pass by Earth was above the west coast of North America at 04:25 UTC on July 3, 2006.
The asteroid's distance from Earth's center of mass at that moment was 0.0028906 AU (432,430 km; 268,700 mi), or just 1.1 times the Moon's average distance from Earth. It was observed immediately after this close approach by radar from three locations, from Goldstone in the Mojave Desert in the USA, from Sicily, and from Yevpatoria RT-70 radio telescope, Ukraine, as well as optically from other
3753 Cruithne ( /ˈkrɪnjə/, from Old Irish [ˈkrɪθnɛ]; Modern [ˈkrɪhnʲə] or [ˈkrɪnʲə]) is an asteroid in orbit around the Sun in 1:1 orbital resonance with the Earth. It is a minor planet that orbits the Sun in a horseshoe orbit relative to Earth. It has been incorrectly called "Earth's second moon", but it is a quasi-satellite, not a moon. Cruithne does not orbit Earth, and at times it is on the other side of the Sun. Its orbit takes it inwards towards the orbit of Mercury, and outside the orbit of Mars. Cruithne orbits the Sun in about 1 year, but it takes 770 years for the series to complete a horseshoe-shaped movement, with the Earth in the gap of the horseshoe.
The name Cruithne is from Old Irish, the Celtic term for the Picts, as well as the name of a people of eastern Ulster.
Cruithne was discovered on October 10, 1986, by Duncan Waldron on a photographic plate taken with the UK Schmidt Telescope at Siding Spring Observatory, Coonabarabran, Australia. The 1983 apparition (1983 UH) is credited to Giovanni de Sanctis and Richard M. West of the European Southern Observatory in Chile. It was not until 1997 that its unusual orbit was determined by Paul Wiegert and Kimmo Innanen,
624 Hektor is the largest Jupiter Trojan. It was discovered in 1907 by August Kopff.
Hektor is a D-type asteroid, dark and reddish in colour. It lies in Jupiter's leading Lagrangian point, L4, called the 'Greek' node after one of the two sides in the legendary Trojan War. Hektor is named after the Trojan hero Hektor and is thus one of two trojan asteroids that is "misplaced" in the wrong camp (the other being 617 Patroclus in the Trojan node).
Hektor is one of the most elongated bodies of its size in the Solar System, being 370 × 200 km. It is thought that Hektor might be a contact binary (two asteroids joined by gravitational attraction) like 216 Kleopatra. Hubble Space Telescope observations of Hektor in 1993 did not show an obvious bilobate shape because of a limited angular resolution. On 17 July 2006, the Keck-10m II telescope and its Laser guide star Adaptive Optics (AO) system indicated a bilobate shape for Hektor. Additionally, a 15-km moonlet at 1000 km of Hektor was detected. The satellite's provisional designation is S/2006 (624) 1. Hektor is, so far, the only known binary trojan asteroid in the L4 point and the first trojan with a satellite companion. 617 Patroclus,
66 Maja ( /ˈmaɪ.ə/) is a dark, quite large main-belt asteroid. It was discovered by Horace Tuttle on April 9, 1861, and named after Maia, one of the Pleiades in Greek mythology.
Maja has been studied by radar.
10000 Myriostos is a main-belt asteroid discovered by A. G. Wilson on September 30, 1951 at the Palomar Observatory on Palomar Mountain, California.
Given the provisional designation 1951 SY, it was renamed "(10000) Myriostos" (Greek for "ten thousandth") to honor all astronomers who helped discover ten thousand such bodies. This occurred after some debate as to whether Pluto should have been reclassified as a minor planet and given the number 10000, with strong resistance coming from the American Astronomical Society's Division for Planetary Sciences.
422 Berolina is a typical Main belt asteroid.
It was discovered by G. Witt on October 8, 1896 in Berlin. It was first of his two asteroid discoveries. The other was the famous asteroid 433 Eros.
Although it has an orbit similar to the Flora family asteroids, it appears to be an unrelated interloper due to not being of the S spectral type (see the PDS asteroid taxonomy data set).
56 Melete ( /ˈmɛlɨtiː/ MEL-i-tee) is a large and dark main belt asteroid. It is a rather unusual P-type asteroid, probably composed of organic rich silicates, carbon and anhydrous silicates, with possible internal water ice.
Melete was discovered by Hermann Goldschmidt from his balcony in Paris, on September 9, 1857. It orbit was computed by E. Schubert, who named it after Melete, the Muse of meditation in Greek mythology.
To date, two stellar occultations by Melete have been observed successfully (in 1997 and again in 2002).
Melete has been studied by radar.
61 Danaë ( /ˈdænəjiː/ DAN-ə-yee or /dəˈneɪ.ə/ də-NAY-ə) is a moderately large, rocky main belt asteroid. It was discovered by Hermann Goldschmidt on September 9, 1860 from his balcony in Paris.
Goldschmidt was ill when asked to name the asteroid, and requested his fellow asteroid-hunter Robert Luther to name it instead. Luther chose to name it after Danaë, the mother of Perseus in Greek mythology. Danaë was the first asteroid to have a diacritical character in its official name.
In 1985, a study of lightcurve data suggested that Danaë may have a moon. If so, the main body would be an ellipsoid measuring 85×80×75 km, and the moon would orbit 101 km away, measuring 55×30×30 km. The density of both would be 1.1 g/cm³.
2005 CB79 is a trans-Neptunian object that is a member of the Haumea family.
As a member of the Haumea family, 2005 CB79 is suspected of being an icy mantle collisional fragment from dwarf planet Haumea. With an absolute magnitude (H) of 4.7, and a Haumea-family albedo of 0.7, this object would have a diameter of 158 km.
Observations by Mike Brown in 2012 using the W. M. Keck Observatory suggest that 2005 CB79 does not have a companion.
43 Ariadne ( /ˌæriˈædniː/) is a fairly large and bright main-belt asteroid. It is the second-largest member of the Flora asteroid family. It was discovered by N. R. Pogson on April 15, 1857, and named after the Greek heroine Ariadne.
Ariadne is very elongate (almost twice as long as its smallest dimension) and probably bi-lobed or at least very angular. It is a retrograde rotator, although its pole points almost parallel to the ecliptic towards ecliptic coordinates (β, λ) = (-15°, 253°) with a 10° uncertainty. This gives an axial tilt of about 105°.
1001 Gaussia is a main-belt asteroid orbiting the Sun. Initially it received the designation 1923 OA. Later it was named after the mathematician Carl F. Gauss. It has a mean visual magnitude of 9.77. Observation of the change in magnitude of this minor planet suggests it has a rotation period of 9.127 ± 0.002 h. Over this period it undergoes variation in magnitude of 0.16.
11714 Mikebrown (1998 HQ51) is a main-belt asteroid discovered by Lowell Observatory. It is named after the astronomer Michael E. Brown.
Mikebrown is unusually eccentric and not very bright. With an absolute magnitude (H) of only 13.9, it is likely less than 10km in diameter.
Astronomers have not noticed any outbursts by Mikebrown.
On May 15th, 2012, Mikebrown will come within about 14.8 Gm (0.099 AU) of Xenia.
21 Lutetia is a large main-belt asteroid of an unusual spectral type. It measures about 100 kilometers in diameter (120 km along its major axis). It was discovered in 1852 by Hermann Goldschmidt, and is named after Lutetia, the Latin name of the city that stood where Paris was later built.
Lutetia has an irregular shape and is heavily cratered, with the largest impact crater reaching 45 km in diameter. The surface is geologically heterogeneous and is intersected by a system of grooves and scarps, which are thought to be fractures. It has a high average density, meaning that it is made of metal-rich rock.
The Rosetta probe passed within 3,162 km (1,965 mi) of Lutetia in July 2010. It was the largest asteroid visited by a spacecraft until the Dawn mission arrived at 4 Vesta in July 2011.
Lutetia was discovered on November 15, 1852, by Hermann Goldschmidt from the balcony of his apartment in Paris. A preliminary orbit for the asteroid was computed in November–December 1852 by German astronomer Georg Rümker and others. In 1903, it was photographed at opposition by Edward Pickering at Harvard College Observatory. He computed an opposition magnitude of 10.8.
There have been two reported
28978 Ixion is a plutino (an object that has a 2:3 orbital resonance with Neptune). It is considered very likely to be a dwarf planet, although the IAU has not officially classified it as such. Light-curve-amplitude analysis shows only small deviations, which suggests that Ixion is a spheroid with small albedo spots and hence a dwarf planet. Tancredi (2010) thinks that Ixion is very probably a dwarf planet. Its diameter of 650 km estimated by Spitzer makes it about the fifth largest plutino. It is moderately red in visible light and has a surface made of a mixture of tholin and water ice.
It was discovered on May 22, 2001. Ixion was discovered by the Cerro Tololo Inter-American Observatory (807). It is named after Ixion, a figure from Greek mythology.
Other than Pluto, Ixion was the first TNO discovered that was originally estimated to be larger than asteroid Ceres, Even in 2002, a year after its discovery, Ixion was still believed to be more than 1000 km in diameter, though the 2002 estimate was a result of a spurious detection at 250 GHz that was not confirmed by later observations. More recent estimates suggest that Ixion has a high albedo and is smaller than Ceres. Observations
Asteroid 3163 Randi was discovered on August 28, 1981 by Charles T. Kowal at Palomar Observatory, California. It has an orbital period of 3.705 years and a semi-major axis of 2.395 AU and is a Mars-crosser asteroid.
It is named in honor of the magician and scientific skeptic James Randi.
773 Irmintraud is a minor planet that orbits the Sun between the planets Mars and Jupiter. Discovered by German astronomer Franz Kaiser at Heidelberg, Germany, on December 22, 1913, the planetoid was named for Irmtraud, an old German woman's name that appears frequently in old songs and sagas. This D-type asteroid's previous designation was 1913 TV. The 773 Irmintraud asteroid is a likely source of the Tagish Lake meteorite which landed in Canada on January 18, 2000.
On December 22, 1913, German astronomer Franz Kaiser discovered 773 Irmintraud at Heidelberg, Germany.
In 1992, Larry A. Lebofsky and colleagues published an article in which they noted that "unaltered asteroids are thought to represent the raw materials available for terrestrial planet formation and so are important to our understanding of the origin and evolution of the Solar System." Since at least 1980, it was believed that D-type asteroids were unaltered asteroids, ultraprimitive in composition and composed largely of hydrated silicates and organic material. However, in analyzing the spectra of 773 Irmintraud for the water of hydration band (the 3-µm absorption feature of hydrated silicates), Lebofsky discovered
159743 Kluk is an asteroid. It was discovered by Jana Tichá and Miloš Tichý at the Kleť Observatory near České Budějovice, Czech Republic, on March 23, 2003. Its provisional designation was 2003 FW1. It is named after a granulite hill near Mount Kleť.
Asteroid 2007 TU24 was discovered by the Catalina Sky Survey in Arizona on October 11, 2007. Imaging radar has estimated that it is 250 meters (820 ft) in diameter. The asteroid passed 554,209 kilometer (344,370 mile or 1.4-lunar distance) from Earth on January 29, 2008, at 08:33 UTC. (At the time of the passage it was believed the closest for any known potentially hazardous asteroid (PHA) of this size before 2027, but in 2010 2005 YU55 was measured to be 400 meters in diameter.) At closest approach the asteroid had an apparent magnitude of 10.3 and was about 50 times fainter than the naked eye can see. It required about a 3-inch (76 mm) telescope to be seen.
From the date of discovery of asteroid 2007 TU24 on 11 October 2007, a total of 316 observations of it had been made by 31 January 2008, spanning 112 days. The trajectory is well defined. It was removed from the 'current impact risks' page of the NASA website on 4 December 2007 at 14:05 UTC.
Goldstone Observatory carried out radar observations on January 23 and January 24, 2008. As of January 24, the orbit of the asteroid was known with such a high precision that scientists were able to calculate close approaches from the year
298 Baptistina is an asteroid orbiting in the asteroid belt and part of the Baptistina family of asteroids. It was discovered on September 9, 1890 by Auguste Charlois of Nice. The reason for its name is unknown. It measures around 13–30 km in diameter. Although it has an orbit similar to the Flora family asteroids, Baptistina was found to be an unrelated interloper. It was considered the possible source of the impactor said to have caused the extinction of the dinosaurs, a possibility ruled out by the Wide-field Infrared Survey Explorer in 2011.
In 2007, a study by William F. Bottke, David Vokrouhlický and David Nesvorný proposed that several known asteroids can be regarded as the "Baptistina family" because they share similar orbital elements. Further, the study argues that the family is the remnant of a 170 km (110 mi) parent asteroid that was destroyed in a collision with a smaller body some 80 million years ago, with Baptistina itself being the largest remnant. Until recently, it was believed that this collision event occurred 160 million years ago. This led to a suggestion that one fragment from the event may have eventually become the K–T impactor believed to have caused the
3806 Tremaine is a small asteroid of the Alinda family. It was first sighted on 14 October 1975 and given the provisional designation 1975 TY5. Two more sightings occurred (1979 SC11 and 1979 TL2) before the March 1, 1981 sighting by Schelte J. Bus (provisional designation 1981 EW32) finally nailed down the orbit.
It is named for the noted Canadian astrophysicist Scott Tremaine.
3908 Nyx is an Amor and Mars-crosser asteroid. It was discovered by Hans-Emil Schuster on August 6, 1980, and is named after Nyx, the Greek goddess of the night, after which Pluto's moon Nix is also named. It is 1–2 km in diameter and is a V-type asteroid, meaning that it may be a fragment of the asteroid 4 Vesta.
In 2000, radar observations conducted at the Arecibo and Goldstone observatories produced a model of Nyx's shape; the asteroid can best be described as spherical but with many protruding lumps.
To avoid confusion with 3908 Nyx, Pluto's moon Nix was changed from the initial proposal of the classical spelling Nyx, to Nix.
10002 Bagdasarian is a main belt asteroid orbiting the Sun. It completes one orbit ever 5.6 years.
The asteroid was discovered by L. I. Chernykh at the Crimean Astrophysical Observatory, and given the provisional designation 1969 TQ1. It was later renamed for Alexandr Sergeevich Bagdasarian, a radio and electronics specialist from Moscow.
20000 Varuna is a large classical Kuiper belt object. It previously had the provisional designation 2000 WR106 and has been precovered in plates dating back to 1953. The IAU has not classified it as a dwarf planet, but Brown and Tancredi consider it likely to be one, and Tancredi (2010) thinks that Varuna is very probably a dwarf planet.
Varuna is named after the Hindu deity, Varuṇa. Varuṇa was one of the most important deities of the ancient Indians, and he presided over the waters of the heaven and of the ocean and as the guardian of immortality. Due to his association with the waters and the ocean, he is often identified with Greek Poseidon and Roman Neptune. Varuna received the minor planet number 20000 because it was the largest cubewano found so far, and was believed to be as large as Ceres.
The size of the large Kuiper belt objects can be determined by simultaneous observations of thermal emission and reflected sunlight. Unfortunately, thermal measures, intrinsically weak for distant objects, are further hampered by the absorption of the Earth's atmosphere as only the weak 'tail' of the emissions is accessible to Earth-based observations. In addition, the estimates are
21711 Wilfredwong is an minor planet discovered on September 7, 1999 by MIT Lincoln Laboratory's Near-Earth Asteroid Research (LINEAR) program. It lies in the Ceres belt of the solar system.
It was named in honor of Wilfred Wong (born 1988), who was awarded second place in the 2006 Intel International Science and Engineering Fair for his engineering project, Polycaprolactone-Chitosan Nanocomposite Biomaterials for Tissue Engineering and Wound Healing.
3200 Phaethon ( /ˈfeɪ.əθɒn/ FAY-ə-thon, sometimes incorrectly spelled Phaeton) is an asteroid with an unusual orbit that brings it closer to the Sun than any other named asteroid (though there are several unnamed asteroids, including three numbered ones, with smaller perihelia, e.g. (137924) 2000 BD19). For this reason, it was named after the Greek myth of Phaëton, son of the sun god Helios. It is 5.10 km in mean diameter.
Phaethon was the first asteroid to be discovered using images from a spacecraft. Simon F. Green and John K. Davies discovered it in images from October 11, 1983 while searching Infrared Astronomical Satellite (IRAS) data for moving objects. It was announced on October 14 in IAUC 3878 along with optical confirmation by Charles T. Kowal, who reported it to be asteroidal in appearance. Its provisional designation was 1983 TB.
It is categorized as an Apollo asteroid (because its semi-major axis is greater than that of the Earth's and its perihelion is less than 1.017 astronomical units. It is also suspected to be a member of the Pallas family of asteroids.
Phaethon's most remarkable distinction is that it approaches the Sun closer than any other named asteroid: its
4660 Nereus ( /ˈnɪəriəs/ NEER-ee-əs; Greek: Νηρέας) is a small (about 0.33 kilometres (0.21 mi)) asteroid. It was discovered by Eleanor F. Helin on February 28, 1982, approximately 1 month after a near pass by the Earth. It is named after Nereus, a Titan in Greek mythology.
Nereus is potentially a very important asteroid. It is an Apollo and Mars-crosser, with an orbit that frequently comes very close to Earth, and because of this it is exceptionally accessible to spacecraft. Indeed, because of its small size and close orbit, its delta-V for rendezvous of ~5 km/s is smaller than the Moon's, which is about 6.3 km/s.
Nereus makes seven approaches to Earth of less than 5 million km between 1900 and 2100. The closest will be in February 2060, at 1.2 million km. The next close approach is in December 2021, when it will be 3.9 million km away. Its orbital period of 1.82 yr also puts it somewhat near a 2:1 orbital resonance with Earth, which means that an approximately 4-year mission could depart for and return from the asteroid on relatively near passes to the Earth.
Nereus was scheduled for visitation by both the private Near Earth Asteroid Prospector (NEAP) probe, and the Japanese
8 Flora is a large, bright main-belt asteroid. It is the innermost large asteroid: no asteroid closer to the Sun has a diameter above 25 kilometres or two-elevenths that of Flora itself, and not until the tiny 149 Medusa was discovered was a single asteroid orbiting at a closer mean distance known. It is the seventh brightest asteroid with a mean opposition magnitude of +8.7. Flora can reach a magnitude of +7.9 at a favorable opposition near perihelion, such as occurred in November 2007. Flora may be the residual core of an intensely heated, thermally evolved, and magmatically differentiated planetesimal which was subsequently disrupted.
Flora was discovered by J. R. Hind on October 18, 1847. It was his second asteroid discovery after 7 Iris.
The name Flora was proposed by John Herschel, from Flora, the Latin goddess of flowers and gardens, wife of Zephyrus (the personification of the West wind), and mother of Spring. The Greek equivalent is Chloris, who has her own asteroid, 410 Chloris, but in Greek Flora is also called Chloris (8 Χλωρίς).
Lightcurve analysis indicates that Flora's pole points towards ecliptic coordinates (β, λ) = (16°, 160°) with a 10° uncertainty. This gives an
9956 Castellaz is a main belt asteroid. It orbits the Sun once every 3.29 years.
Discovered on October 5, 1991 by L. D. Schmadel and F. Borngen it was given the provisional designation "1991 TX4". It was later renamed "Castellaz" after German physicist Peter Castellaz.
9997 COBE is a main belt asteroid. It orbits the Sun once every 4.06 years.
Discovered on March 25, 1971 by C. J. van Houten and I. van Houten-Groeneveld in archival data produced by T. Gehrels, it was given the provision designation 1217 T-1. It was later renamed 9997 COBE in honour of the Cosmic Background Explorer.
2004 FH is a near-Earth asteroid that was discovered on March 15, 2004, by the NASA-funded LINEAR asteroid survey. The object is roughly 30 metres in diameter and passed just 43,000 km (27,000 mi) above the Earth's surface on March 18, 2004, at 22:08 UTC; making it the 11th closest approach to Earth recorded as of 21 November 2008 (2008 -11-21) (see the diagram below). For comparison, geostationary satellites orbit Earth at 35,790 km.
2004 FH is an Aten family asteroid, although by some definitions it should be called a meteoroid, since it is smaller than 50 metres in diameter. Despite its relatively small size (about 30 metres), it is still the fourth largest asteroid detected coming closer to the Earth than the Moon.
Had this object hit Earth, it would probably have detonated high in the atmosphere. It might have produced a blast measured in hundreds of kilotons of TNT, but may not have produced any effect on the ground. It could also have been an Earth-grazing fireball if it had been much closer but not close enough to impact.
On 2044-Mar-17 the asteroid will pass no closer than 0.0116 AU (1,740,000 km; 1,080,000 mi) from the Earth. 2004 FH also has the distinction of having the
32 Pomona is a main-belt asteroid. It was discovered by H. Goldschmidt on October 26, 1854, and is named after Pōmōna, the Roman goddess of fruit trees.
Australian amateur astronomer Jonathan Bradshaw recorded an unusual asteroid occultation by 32 Pomona on 16 August 2008. The expected maximum duration of the occultation was 7.1 secs; however, the video recording shows two separate occultations of equal depth each lasting 1.2 seconds, separated by 0.8 secs. Those durations convert to chord lengths at the asteroid of 15 km, 10 km, and 15 km – for a total length of 40 km. The IRAS diameter for Pomona is 80.8 ± 1.6 km. The most likely explanation for this observation is that the asteroid is either binary (including a contact binary), or is a unitary asteroid with a significant concave region on its surface. The video of this occultation can be viewed on YouTube.
9987 Peano is a main belt asteroid. It orbits the Sun once every 3.38 years.
Discovered by P. G. Comba on July 29, 1997 it was given the provisional designation 1997 OO1. It was later renamed 9987 Peano in honour of Giuseppe Peano.
9957 Raffaellosanti is a main belt asteroid. It orbits the Sun once every 3.46 years.
Discovered on October 6, 1991 by F. Börngen, it was given the provisional designation "1991 TO13". It was later renamed "Raffaellosanti" after Raffaello Sanzio, a master of the Italian Renaissance.
(66391) 1999 KW4 (also written (66391) 1999 KW4) is an Aten and Mercury-crosser asteroid discovered by LINEAR in 1999.
1999 KW4 has a moon orbiting it. The moon, designated S/2001 (66391) 1 or '1999 KW4 Beta' is ~360 m in diameter, and orbits 1999 KW4 'Alpha' in 0.758 d (16 hours) at a distance of 2.6 km. The presence of a companion was suggested by photometric observations made June 19–27, 2000 by Petr Pravec and Lenka Šarounová at Observatoř Ondřejov (Ondřejov Observatory) and was confirmed by radar observations from Arecibo Observatory from May 21-23, 2001 by Lance A. M. Benner, Steven J. Ostro, Jon D. Giorgini, Raymond F. Jurgens, Jean-Luc Margot and Michael C. Nolan, announced on May 23, 2001.
The shapes of the two bodies and their dynamics are complex. Among other bizarre properties, the equatorial regions of Alpha are very close to breakup: raising a particle a meter above the surface would put it into orbit around the object.
17 Thetis is a large main-belt asteroid. It is an S-type asteroid, therefore giving it a relatively bright silicate surface.
It was discovered by R. Luther on April 17, 1852. It was his first asteroid discovery. Its name comes from Thetis, the mother of Achilles in Greek mythology.
One Thetidian stellar occultation was observed from Oregon in 1999. However, the event was not timed.
The mass of Thetis has been calculated from perturbations by 4 Vesta and 11 Parthenope. In 2007, Baer and Chesley calculated Thetis to have a mass of 1.2×10 kg with a density of 3.21 g/cm³.
243 Ida (/ˈaɪdə/ EYE-də) is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Johann Palisa and named after a nymph from Greek mythology. Later telescopic observations categorized Ida as an S-type asteroid, the most numerous type in the inner asteroid belt. On 28 August 1993, Ida was visited by the spacecraft Galileo, bound for Jupiter. It was the second asteroid to be visited by a spacecraft and the first found to possess a satellite.
Like all main-belt asteroids, Ida's orbit lies between the planets Mars and Jupiter. Its orbital period is 4.84 years, and its rotation period is 4.63 hours. Ida has an average diameter of 31.4 km (19.5 mi). It is irregularly shaped and elongated, and apparently composed of two large objects connected together in a shape reminiscent of a croissant. Its surface is one of the most heavily cratered in the Solar System, featuring a wide variety of crater sizes and ages.
Ida's moon, Dactyl, was discovered by mission member Ann Harch in images returned from Galileo. It was named after the Dactyls, creatures which inhabited Mount Ida in Greek mythology. Dactyl, being only 1.4 kilometres (4,600 ft) in diameter,
375 Ursula is one of the largest asteroids from the asteroid belt. It was discovered by Auguste Charlois on September 18, 1893, in Nice.
Observations of an occultation on November 15, 1984, produced six chords indicating an estimated diameter of 216±10 km.
702 Alauda is a large minor planet, measuring 194.73 km in diameter. It was discovered in 1910 by Joseph Helffrich from the observatory at Heidelberg University. It is named after the lark (alauda). In 2007, a small moon, named Pichi üñëm, was discovered.
Alauda's satellite was discovered from observations using adaptive-optics imaging with the European Southern Observatory (ESO) 8-m Very Large Telescope (VLT) on Cerro Paranal, Chile. It is 5.5 km in diameter and has a projected separation from Alauda of 900 km. It was named Pichi üñëm, meaning "little bird" in the Mapuche language of Chile, the country from which the moon was discovered.
Alauda has been identified as the largest member of a dynamical family. Other members of this family include: 581 Tauntonia, 1101 Clematis, 1838 Ursa, 3139 Shantou, 3325 TARDIS, 4368 Pillmore, 5360 Rozhdestvenskij, 5815 Shinsengumi, and many others. Alauda's moon may be a result of the collision that created the asteroid family.
The discovery of Alauda's moon enabled Alauda's mass to be determined. Rojo and Margot (2010) have estimated its mass to be 6.06×10 kg with a density of 1.57 g/cm³.
Alauda has been observed to occult stars on several
9 Metis is one of the larger main-belt asteroids. It is composed of silicates and metallic nickel-iron, and may be the core remnant of a large asteroid that was destroyed by an ancient collision. Metis is estimated to contain just under half a percent of the total mass of the asteroid belt.
Metis was discovered by Andrew Graham on 25 April 1848, at Markree Observatory in Ireland; it was his only asteroid discovery. It also has been the only asteroid to have been discovered as a result of observations from Ireland until 7 October 2008, when, 160 years later, Dave McDonald from observatory J65 discovered 2008 TM9. Its name comes from the mythological Metis, a Titaness and Oceanid, daughter of Tethys and Oceanus. The name Thetis was also considered and rejected (it would later devolve to 17 Thetis).
Metis' direction of rotation is unknown at present, due to ambiguous data. Lightcurve analysis indicates that the Metidian pole points towards either ecliptic coordinates (β, λ) = (23°, 181°) or (9°, 359°) with a 10° uncertainty. The equivalent equatorial coordinates are (α, δ) = (12.7 h, 21°) or (23.7 h, 8°). This gives an axial tilt of 72° or 76°, respectively.
Hubble space telescope
9964 Hideyonoguchi is a main belt asteroid. It orbits the Sun once every 3.88 years.
Discovered on February 13, 1992 by T. Seki, it was given the provisional designation "1992 CF1". It was later renamed "Hideyonoguchi" after Hideyo Noguchi, a bacteriologist who made important advances in medicine working at the Rockefeller Institute for Medical Research.
809 Lundia is a small, binary, V-type asteroid orbiting within the Flora family in the main belt. It is named after Lund Observatory, Sweden.
Lundia orbits within the Flora family. However, its V-type spectrum indicates that it is not genetically related to the Flora family, but rather is probably a fragment (two fragments if one includes its moon) ejected from the surface of 4 Vesta by a large impact in the past. Its orbit lies too far from Vesta for it to actually be a member of the Vesta family. It is not clear how it arrived at an orbit so far from Vesta, but other examples of V-type asteroids orbiting fairly far from their parent body are known. A mechanism of interplay between the Yarkovsky effect and nonlinear secular resonances (primarily involving Jupiter and Saturn) has been proposed.
Lightcurve observations in 2005 revealed that Lundia is a binary system of two similarly sized objects orbiting their common centre of gravity. "Lundia" now refers to one of the objects, the other being provisionally designated S/2005 (809) 1. The similarity of size between the two components is suspected because during mutual occultations the brightness drops by a similar amount
The asteroid 2685 Masursky is a main-belt asteroid. It was discovered by Edward (Ted) Bowell in 1981. It was named after Harold Masursky (1923–1990), a planetary geologist at the U.S. Geological Survey, Flagstaff, who worked on numerous space missions.
Little was known about Masursky until the Cassini space probe, en route to Jupiter and Saturn, flew past it on 23 January 2000. Since Cassini passed the asteroid at a distance of 1.6 million kilometres (about four times the Earth–Moon distance), the images it returned showed nothing more than a dot. Nevertheless, Cassini was able to determine Masursky's size (about 15–20 km in diameter).
Masursky's orbit places it within the Eunomia family of S-type asteroids. Cassini's observations had cast some doubt on its composition, but later ground-based spectroscopy has confirmed its S-type spectrum.
42 Isis ( /ˈaɪsɨs/) is a large main-belt asteroid, measuring 100.2km in diameter. It was discovered by N.R. Pogson on May 23, 1856, at Oxford. It was Pogson's first asteroid discovery.
The asteroid's name was chosen by Manuel John Johnson, director of the Radcliffe Observatory in Oxford. Although Isis is the name of an Egyptian goddess, the name was probably chosen in homage to Pogson's astronomer daughter, Elizabeth Isis Pogson. In addition, the Isis is the stretch of the River Thames that runs through Oxford.
5381 Sekhmet is an Aten asteroid whose orbit is sometimes closer to the Sun than the Earth's. It was discovered on 14 May 1991 by Carolyn Shoemaker at Palomar Observatory. It is named after Sekhmet, the Egyptian goddess of war.
Sekhmet is believed to be an S-type asteroid, and to measure approximately 1 km in diameter.
In December 2003, a team of astronomers at Arecibo Observatory announced that the asteroid may have a moon that measures 300 m in diameter and orbits approximately 1.5 km from Sekhmet. This moon is not yet confirmed.
58 Concordia is a fairly large asteroid-belt asteroid. It is classified as a C-type asteroid, meaning that its surface is very dark and it is likely carbonaceous in composition.
Concordia was discovered by Robert Luther on March 24, 1860. At Luther's request, it was named by Carl Christian Bruhns of the University of Leipzig after Concordia, the Roman goddess of harmony.
951 Gaspra ( /ˈɡæsprə/) is an S-type asteroid that orbits very close to the inner edge of the asteroid belt. Gaspra was the first asteroid ever to be closely approached when it was visited by the Galileo spacecraft, which flew by on its way to Jupiter on 29 October 1991.
Apart from a multitude of small craters, Gaspra has half a dozen large flat areas and concavities. One of these flat areas, (Dunne Regio), is a 5×7 km area which is flat to within 200 m. It is uncertain whether these are the result of impacts or whether they are instead facets formed when Gaspra broke off its parent asteroid. In the weak, lopsided gravity of Gaspra, impact craters would naturally take on such flat, lopsided shapes, making this determination difficult. The flat facets and concavities give Gaspra a very angular appearance.
Gaspra appears to be fairly olivine-rich among the S-type asteroids (the surface appears to contain olivine and pyroxene in the proportions 4:1 to 7:1). There are no prominent albedo or color patterns, although a subtle color variation is seen across the surface (see image above).
Gaspra's surface lacks unambiguous craters of a size comparable to its radius, like those seen for
9963 Sandage is a main belt asteroid. It orbits the Sun once every 3.58 years.
Discovered on January 9, 1992 by E. F. Helin, it was given the provisional designation "1992 AN". It was later renamed "Sandage" after Allan Sandage, an American astronomer.
(26308) 1998 SM165, also written as (26308) 1998 SM165, is a binary trans-Neptunian object (TNO) that resides in the Kuiper belt. It was discovered on September 16, 1998, by Nichole M. Danzl. It is in a 1:2 orbital resonance with the planet Neptune.
1998 SM165 has a semi-major axis (average distance from the Sun) near the edge of the classical belt. Both the Minor Planet Center (MPC) and the Deep Ecliptic Survey (DES) list this trans-Neptunian object as a twotino. For every one orbit that a twotino makes, Neptune orbits twice.
The observations with the infrared Spitzer Space Telescope combined with the orbits established using the Hubble Telescope allow the estimation of the density, assuming the components of equal albedo.
The resulting estimate of 0.51 +0.29
−0.14 g/cm is similar to the density of the binary plutino (47171) 1999 TC36 (0.3–0.8 g/cm ) and the Saturn’s moon Hyperion (0.567 ± 0.102 g/cm ) Such a low density is indicative of a highly porous composition dominated by ice.
Designated S/2001 (26308) 1, it is about 96±12 km in diameter and it orbits its primary at a distance of 11,310±110 km. Assuming a circular orbit, this takes 130.1±1 days to complete one orbit.
14 Irene is a large main-belt asteroid.
14 Irene was discovered by J. R. Hind on May 19, 1851, and named after Irēnē, a personification of peace in Greek mythology. She was one of the Horae, daughter of Zeus and Themis. The name was suggested by Sir John Herschel. Hind wrote,
The Great Exhibition of the Works of Industry of All Nations in the Crystal Palace of Hyde Park, London, ran from May 1 until October 18, 1851.
Hind suggested that the symbol for the asteroid should be "A dove carrying an olive-branch, with a star on its head", but an actual drawing of the symbol was never made before the use of graphical symbols to represent asteroids was dropped entirely.
The fairly flat Irenian lightcurves indicate somewhat spherical proportions. There have been four reported stellar occultation events by Irene.
153 Hilda is a large asteroid in the outer main belt, with a diameter of 170 km. Because it is composed of primitive carbonaceous materials, it has a very dark surface. It was discovered by Johann Palisa on November 2, 1875 from the Austrian Naval Observatory at Pula. The name was chosen by the astronomer Theodor von Oppolzer, who named it after one of his daughters.
Hilda gives its name to an asteroid group called the Hilda family (or Hildas for short). It is not a true asteroid family, since the members are not physically related, but rather share similar orbital elements. The Hildas are locked in a 2:3 orbital resonance with Jupiter; since Jupiter takes 11.9 years to orbit the Sun while Hilda takes 7.9 years, Jupiter orbits the Sun twice for every 3 orbits that Hilda completes. There are over 1,100 other objects known to be in a 2:3 resonance with Jupiter.
Hilda was observed to occult a star on December 31, 2002, from Japan. It has a very low-amplitude light curve indicating a spherical body or a non-varying albedo.
The asteroid 1620 Geographos ( /dʒiːoʊˈɡræfɒs/) was discovered on September 14, 1951 at the Palomar Observatory by Albert George Wilson and Rudolph Minkowski. It was originally given the provisional designation 1951 RA. Its name, a Greek word meaning "geographer" (geo– 'Earth' + graphos 'drawer/writer'), was chosen to honour geographers and the National Geographic Society.
Geographos is a Mars-crosser asteroid and a near-Earth object belonging to the Apollos. In 1994, during the asteroid's closest approach to Earth in two centuries at 5.0 Gm-which will not be bettered until 2586- a radar study of it was conducted by the Deep Space Network at Goldstone, California. The resultant images show Geographos to be the most elongated object in the solar system; it measures 5.1×1.8 km.
Geographos is an S-type asteroid, meaning that it is highly reflective and composed of nickel-iron mixed with iron- and magnesium-silicates.
Geographos was to be explored by the U.S.'s Clementine mission; however, a malfunctioning thruster ended the mission before it could approach the asteroid.
49 Pales ( /ˈpeɪliːz/) is a large, dark main-belt asteroid. It was discovered by Hermann Goldschmidt on September 19, 1857 from his balcony in Paris.
The asteroid is named after Pales, the goddess of shepherds in Roman mythology. Since it was discovered on the same night as 48 Doris, geologist Élie de Beaumont suggested naming the two "The Twins".
Pales has been studied by radar.
6223 Dahl is an asteroid discovered 3 September 1980 by Antonín Mrkos at the Kleť Observatory in České Budějovice, Czech Republic. It was named in honor of the Welsh author Roald Dahl.
See also: List of asteroids.
9993 Kumamoto is a main belt asteroid. It orbits the Sun once every 4.04 years.
Discovered by J. Kobayashi on November 6, 1997 it was given the provisional designation 1997 VX5. It was later renamed Kumamoto in honour of Kumamoto, the home city of the asteroid's discoverer.
Ceres, formally 1 Ceres, is the only dwarf planet in the inner Solar System, and the largest asteroid. It is a rock–ice body 950 km (590 mi) in diameter, and though the smallest identified dwarf planet, it constitutes a third of the mass of the asteroid belt. Discovered on 1 January 1801 by Giuseppe Piazzi, it was the first asteroid to be identified, though it was classified as a planet at the time. It is named after Ceres, the Roman goddess of growing plants, the harvest, and motherly love.
The Cererian surface is probably a mixture of water ice and various hydrated minerals such as carbonates and clays. It appears to be differentiated into a rocky core and icy mantle, and may harbour an ocean of liquid water under its surface. From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, and hence even at its brightest it is still too dim to be seen with the naked eye except under extremely dark skies. The unmanned Dawn spacecraft, launched on 27 September 2007 by NASA, is expected to be the first to explore Ceres after its scheduled arrival there in 2015. The spacecraft left asteroid 4 Vesta about 5 September 2012, which it had been orbiting since July 2011.
The idea that
4486 Mithra is an Apollo and Mars-crosser asteroid. It was discovered by Eric Elst and Vladimir Shkodrov on September 22, 1987. It is named after Mithra, Indo-Iranian god of light. In Asia Minor around 330 B.C. the god Mithra was identified with the Greek god Apollo, hence the name.
In 2000 it made a very close approach to Earth, passing 6.96 million km, or 0.047 au from it.
The asteroid measures 2–5 km in diameter. Its shape has been analyzed by radar, and has been revealed as bizarre: it is the most highly bifurcated object in the solar system, with two distinct lobes.
(33342) 1998 WT24 (also written (33342) 1998 WT24) is an Aten asteroid located in Venus' zone of influence that has frequent close encounters with Mercury, Venus, and Earth. It is also one of the best studied potentially hazardous asteroids.
(33342) 1998 WT24 was discovered on November 25, 1998, by LINEAR about four months after a particularly close encounter with the planet Mercury (about 0.047 au). At the time of its discovery, astronomers were trying to find the first Apohele asteroid (one that is always closer to the Sun than the Earth). All asteroids known at the time that got closer to the Sun than the Earth also crossed Earth's orbit. Earlier that year, David J. Tholen claimed to have spotted the first Apohele asteroid, which was dubbed 1998 DK36. However, the object was lost without being confirmed. Thus, 1993 DA remained the asteroid with the lowest known aphelion at 1.023 au. When 1998 WT24 was discovered, it was found to have a slightly smaller aphelion than 1993 DA (1.019 au), and was thus the closest thing to an Apohele asteroid known at the time. It lost its smallest aphelion title almost immediately when 1998 XX2 was discovered only a few weeks later (aphelion =
10199 Chariklo ( /kəˈrɪkloʊ/ kə-RIK-loh, /ˈkærɨkloʊ/ KARR-i-kloh; Greek: Χαρικλώ; provisional designation: 1997 CU26) is the largest known centaur. It orbits the Sun between Saturn and Uranus, grazing Uranus.
Chariklo was discovered by James V. Scotti of the Spacewatch program on February 15, 1997. Chariklo is named after the nymph Chariclo (Χαρικλω), the wife of Chiron and the daughter of Apollo.
A photometric study in 2001 was unable to find a definite period of rotation. Infrared observations of Chariklo indicate water ice on the surface. Mike Brown's website lists it as a possible dwarf planet with a measured diameter of 258 km.
If one knows the absolute magnitude (H) and the albedo of an object, one can estimate the size. But since centaurs are icy comet-like bodies that may outgas, it is very difficult to estimate their albedos. It is also likely that the albedos of some centaurs vary with time and activity levels.
With an absolute magnitude (H) of 6.4 and an albedo of 0.06, Chariklo is currently the largest known centaur with an estimated diameter of 258 km. 2060 Chiron (230 km / H=6.5 / albedo=0.07) is likely a close second. The lost centaur 1995 SN55 (H=6.0) may even be
15 Eunomia is a very large asteroid in the inner asteroid belt. It is the largest of the stony (S-type) asteroids, and somewhere between the 8th-to-12th-largest main-belt asteroid overall (uncertainty in diameters causes uncertainty in its ranking). It is the largest Eunomian asteroid, and is estimated to contain 1% of the mass of the asteroid belt.
Eunomia was discovered by Annibale de Gasparis on July 29, 1851 and named after Eunomia, one of the Horae (Hours), a personification of order and law in Greek mythology.
As the largest S-type asteroid (with 3 Juno being a very close second), Eunomia has attracted a moderate amount of scientific attention. It contains slightly over one percent of the mass of the entire asteroid belt.
Eunomia appears to be an elongated but fairly regularly shaped body, with what appear to be four sides of differing curvature and noticeably different average compositions. Its elongation led to the suggestion that Eunomia may be a binary object, but this has been refuted. It is a retrograde rotator with its pole pointing towards ecliptic coordinates (β, λ) = (-65°, 2°) with a 10° uncertainty. This gives an axial tilt of about 165°.
Like other true members
2008 TC3 (Catalina Sky Survey temporary designation 8TA9D69) was a meteoroid 2 to 5 meters (7 to 16 ft) in diameter and weighing 80 tonnes, that entered Earth's atmosphere on October 7, 2008, at 02:46 UTC (05:46 local time). The meteoroid was notable as the first such body to be observed and tracked prior to reaching Earth. It exploded an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. A search of the impact zone that began on December 2008 turned up 10.5 kilograms (23 lb) of meteorites in 600 fragments, which are surviving pieces of the meteoroid. The meteorites are of a rare type known as ureilites, which contain, among other minerals, nanodiamonds.
The meteoroid was discovered by Richard A. Kowalski at the Catalina Sky Survey (CSS) 1.5-meter telescope at Mount Lemmon, north of Tucson, Arizona, USA, on October 6, 06:39 UTC, about 20 hours before the impact.
The meteoroid was notable as the first such body to be observed and tracked prior to reaching Earth. The process of detecting and tracking a near-Earth object, an effort sometimes referred to as Spaceguard, was put to the test. In total, 586 astrometric and almost as many photometric observations were
35 Leukothea ( /ljuːˈkɒθiə/ lew-KOTH-ee-ə, Greek: Λευκοθέα) is a large, dark main-belt asteroid.
It was discovered by R. Luther on April 19, 1855, and named after Leukothea, a sea goddess in Greek mythology.
37 Fides ( /ˈfaɪdiːz/ FY-deez) is a large main-belt asteroid.
It was discovered by R. Luther on October 5, 1855, and named after Fides, the Roman goddess of loyalty. Fides was the last of the main-belt asteroids to be assigned an iconic symbol.
39 Laetitia ( /lɨˈtiːʃiə/) is a large, bright main-belt asteroid.
Laetitia was discovered by J. Chacornac on February 8, 1856, and named after Laetitia, a minor Roman goddess of gaiety.
Observations of an occultation on March 21, 1998, produced several chords indicating an ellipsoid of 219×142 km.
54509 YORP (2000 PH5) is an Apollo Near-Earth Object (NEO) discovered on August 3, 2000 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) Team at Socorro. Measurements of the rotation rate of this object provided the first observational evidence of the YORP effect, hence the name of the asteroid. The asteroid's rate of rotation is increasing at the rate of (2.0 ± 0.2) × 10 deg/day which between 2001 and 2005 caused the asteroid to rotate about 250° further than its spin rate in 2001 would have predicted. Simulations of the asteroid suggest that it may reach a rotation period of ~20 seconds near the end of its expected lifetime. The simulations also ruled out the possibility that close encounters with the Earth have been the cause of the increased spin rate.
6 Hebe ( /ˈhiːbiː/ HEE-bee) is a large main-belt asteroid, containing around half a percent of the mass of the belt. Its apparently high bulk density (greater than that of the Earth's Moon or even Mars), however, means that by volume it does not rank among the top twenty asteroids. This high bulk density suggests an extremely solid body that has not been impacted by collisions, which is not typical of asteroids of its size – they tend to be loosely bound rubble piles.
In brightness, Hebe is the fifth brightest object in the asteroid belt after Vesta, Ceres, Iris and Pallas. It has a mean opposition magnitude of +8.3, about equal to the mean brightness of Titan and can reach +7.5 at an opposition near perihelion.
Hebe is probably the parent body of the H chondrite meteorites, which account for a remarkable 40% of all meteorites striking the Earth.
Hebe was the sixth asteroid to be discovered, on July 1, 1847 by Karl Ludwig Hencke. It was the second and final asteroid discovery by Hencke, who had previously found 5 Astraea. The name Hebe, goddess of youth, was proposed by Carl Friedrich Gauss.
6 Hebe is the probable parent body of the H chondrite meteorites and the IIE iron
6489 Golevka is an Apollo, Mars-crosser and Alinda asteroid, discovered in 1991 by Eleanor F. Helin.
Its name has a complicated origin. In 1995, Golevka was studied simultaneously by three radar observatories across the world: Goldstone in California, Yevpatoria RT-70 radio telescope in Ukraine (Yevpatoria is sometimes romanized as Evpatoria) and Kashima in Japan. 'Golevka' comes from the first few letters of each observatory's name; it was proposed by the discoverer following a suggestion by Alexander L. Zaitsev.
Golevka is a small object, measuring 0.6 × 1.4 km. The radar observations revealed that it has a very strange, angular shape that looks different depending on the direction. In 2003 the Yarkovsky effect was first observed at work by high-precision radar observations of Golevka. Between 1991 and 2003, the small force of the Yarkovsky Effect caused a shift of 15 kilometers (9.4 miles) from what would be expected based on only gravitational interactions. This helped evaluate the asteroid's bulk density (2.7 ± 0.5 g/cm³) and mass (2.10×10 kg).
It approaches Earth to 0.05 AU (7,500,000 km; 4,600,000 mi) in 2046, 0.10 AU in 2069, and 0.11 AU in 2092. Golevka's collision
9971 Ishihara is a main belt asteroid. It orbits the Sun once every 3.22 years.
Discovered on April 16, 1993 by K. Endate and K. Watanabe it was given the provisional designation 1993 HS. It was later renamed Ishihara after Takahiro Ishihara, a former president of the Hiroshima Astronomical Society.
(55636) 2002 TX300 is a bright Kuiper belt object in the outer Solar System estimated to be about 286 km in diameter. It is a large member of the Haumea family, discovered on October 15, 2002, by the Near-Earth Asteroid Tracking (NEAT) program.
A classical Kuiper belt object with the absolute magnitude between that of 50000 Quaoar and 20000 Varuna, 2002 TX300 has the most eccentric and inclined orbit of the three.
A variability of the visual brightness was also detected which could fit to 7.9 h or 15.8 h rotational period (the distinction between single or double-peaked curved could not be made with confidence). The changes in brightness are quite close to the error margin and could also be due to an irregular shape.
2002 TX300 is classified as a classical Kuiper belt object and follows an orbit very similar to that of Haumea: highly inclined (26°) and moderately eccentric (e ~0.12), far from Neptune’s perturbations (perihelion at ~37 AU). Other mid-sizes cubewanos follow similar orbits as well, notably 2002 UX25 and 2002 AW197.
The diagrams show polar and ecliptic views of the orbits of the two cubewanos. The perihelia (q) and the aphelia (Q) are marked with the dates of passage.
27 Euterpe is a large main-belt asteroid. It was discovered by J. R. Hind on November 8, 1853, and named after Euterpē, the Muse of music in Greek mythology.
Euterpe is one of the brightest asteroids in the night sky. On December 25, 2015, during a perihelic opposition, it will shine with an apparent magnitude of 8.3.
Euterpe has been studied by radar.
48 Doris is one of the largest main belt asteroids. It was discovered by Hermann Goldschmidt on September 19, 1857 from his balcony in Paris.
To find a name for the object, Jacques Babinet of the Academy of Sciences created a shortlist and asked the geologist Élie de Beaumont to make the selection. De Beaumont chose Doris, after an Oceanid in Greek mythology. Since Doris was discovered on the same night as 49 Pales, de Deaumont suggested naming the two "The Twins".
An occultation on March 19, 1981, suggested a diameter of 219±25 km. Observations of an occultation on October 14, 1999, using four well-placed chords, indicate an ellipsoid of 278×142 km and that 48 Doris is an extremely irregular shaped object.
Doris will pass within 0.019 AU of Pallas in June 2132.
48 Doris is a location in the text-based science fiction game Federation 2.
90377 Sedna is a large trans-Neptunian object, which as of 2012 was about three times as far from the Sun as Neptune. Spectroscopy has revealed that Sedna's surface composition is similar to that of some other trans-Neptunian objects, being largely a mixture of water, methane and nitrogen ices with tholins. Its surface is one of the reddest in the Solar System. Neither its mass nor its size are well known and the IAU has not formally recognized it as a dwarf planet, though it is thought to be one by several astronomers.
For most of its orbit it is even farther from the Sun than at present, with its aphelion estimated at 960 astronomical units (32 times Neptune's distance), making it one of the most distant known objects in the Solar System other than long-period comets. Sedna's exceptionally long and elongated orbit, taking approximately 11,400 years to complete, and distant point of closest approach to the Sun, at 76 AU, have led to much speculation as to its origin. The Minor Planet Center currently places Sedna in the scattered disc, a group of objects sent into highly elongated orbits by the gravitational influence of Neptune. However, this classification has been contested, as
9991 Anežka is an outer main belt asteroid. It orbits the Sun once every 5.73 years.
Discovered on October 5, 1997 by Zdeněk Moravec, it was given the provisional designation 1997 TY9. It was later renamed 9991 Anežka to honour the grandmother of its discoverer for her 75th birthday.
9998 ISO is a main belt asteroid. It completes one orbit of the Sun every 3.18 years.
Discovered on March 25, 1971 by C. J. van Houten & I. van Houten-Groeneveld on archival images taken by T. Gehrels, the body was given a provisional designation of 1293 T-1. It was later renamed 9998 ISO to honour the Infrared Space Observatory.
10 Hygiea is the fourth largest asteroid in the Solar System by volume and mass and is located in the asteroid belt. With somewhat oblong diameters of 350–500 km, and a mass estimated to be 2.9% of the total mass of the belt. It is the largest of the class of dark C-type asteroids with a carbonaceous surface.
Despite its size, due to its dark surface and larger-than-average distance from the Sun, it appears very dim when observed from Earth. For this reason several smaller asteroids were observed before Annibale de Gasparis discovered Hygiea on April 12, 1849. At most oppositions, Hygiea has a magnitude that is four orders lower than Vesta's, and observing it will require at least a 100 mm (4-inch) telescope, while at a perihelic opposition, it may be observable with 10x50 binoculars.
Hygiea was discovered by Annibale de Gasparis on April 12, 1849, in Naples, Italy. It was the first of his nine asteroid discoveries. The director of the Naples observatory, Ernesto Capocci, named the asteroid. He chose to call it Igea Borbonica ("Bourbon Hygieia") in honor of the ruling family of the Kingdom of the Two Sicilies where Naples was located.
However, in 1852, John Russell Hind wrote that
20 Massalia is a large and fairly bright main-belt asteroid. It is also the largest member of the Massalia family of asteroids. Its name is the Greek name for Marseille, the city from which one of the two independent co-discovers, Jean Chacornac, first sighted it.
Massalia is an S-type asteroid. It orbits at very low inclination in the intermediate main belt, and is by far the largest asteroid in the Massalia family. The remaining family members are fragments ejected by a cratering event on Massalia.
Massalia has an above-average density for S-type asteroids, similar to the density of silicate rocks. As such, it appears to be a solid un-fractured body, a rarity among asteroids of its size. Apart from the few largest bodies over 400 km in diameter, such as 1 Ceres and 4 Vesta, most asteroids appear to have been significantly fractured, or are even rubble piles. In 1998, Bange estimated Massalia to have a mass of 5.2×10 kg assuming that 4 Vesta has 1.35×10 solar mass. The mass of Massalia is dependent on the mass of 4 Vesta and perturbation of 44 Nysa.
Lightcurve analysis indicates that Massalia's pole points towards either ecliptic coordinates (β, λ) = (45°, 10°) or (β, λ) = (45°,
52872 Okyrhoe ( /əˈkɪroʊ.iː/; from Greek: Ωκυρόη, Ωκυρρόη) is a centaur orbiting in the outer Solar System between Jupiter and Neptune. It was discovered on September 19, 1998, by Spacewatch.
Centaurs have short dynamical lives due to strong interactions with the giant planets. Okyrhoe (1998 SG35) is estimated to have an orbital half-life of about 670 kiloannum.
Of objects listed as a centaur by the Minor Planet Center (MPC), JPL, and the Deep Ecliptic Survey (DES), Okyrhoe has the second smallest perihelion distance. Recently discovered 2008 QD4 has a smaller perihelion distance.
Okyrhoe passed perihelion in early 2008, and exhibited important magnitude variations during March and April 2008. This could be a sign of sublimation of volatiles.
9972 Minoruoda is a C-type main belt asteroid. It orbits the Sun once every 3.46 years.
Discovered on May 26, 1993 by S. Otomo it was given the provisional designation 1993 KQ. It was later renamed "Minoruoda" after Minoru Oda, a former director general of the Institute of Space and Astronautical Science.
15462 Stumegan (1999 AV1) is a Main-belt asteroid discovered on January 8, 1999. The asteroid was discovered at Kitt Peak National Observatory as part of the Spacewatch project.
It is named for Stu Megan, who discovered the first Spacewatch FMO Project asteroid to attain an official IAU MPEC designation.
26328 Litomyšl is a main belt asteroid with an orbital period of 1258.7751929 days (3.45 years).
The asteroid was discovered on November 18, 1998 in Litomyšl, Bohemia, Czech Republic by Miloš Tichý and Zdeněk Moravec.
33 Polyhymnia is a main belt asteroid.
It was discovered by J. Chacornac on October 28, 1854 and named after Polyhymnia, the Greek Muse of sacred hymns.
Due to its high eccentricity (0.338), one of the highest for a lower numbered minor planet, on rare close approaches it can reach tenth magnitude, as on September 8, 2014 when it will be apparent magnitude 9.9 and 0.894 AU from Earth.
Polyhymnia has been studied by radar.
60 Echo is a quite large main-belt S-type asteroid. It was discovered by James Ferguson of the United States Naval Observatory in Washington D.C., on September 14, 1860. It was his third and final asteroid discovery. It is named after Echo, a nymph in Greek mythology.
Echo has been studied by radar.
64 Angelina is a medium-sized main belt E-type asteroid discovered in 1861. It is an unusually bright form of E-type asteroid.
Angelina was discovered on March 4, 1861, by a prolific comet discoverer, E. W. Tempel, observing from Marseilles, France. It was the first of his five asteroid discoveries.
Angelina's name caused some controversy. It was chosen by Benjamin Valz, director of the Marseilles Observatory, in honour of the astronomical station of that name operated by Baron Franz Xaver von Zach on the mountains above the city. At the time, asteroids were supposed to receive names from classical mythology, and several astronomers protested the choice. Tempel noted that if the second 'n' were removed, the complaints would be satisfied (referring to Angelia, a minor Greek deity). However, Valz's choice stayed.
Angelina is an uncommon form of E-type asteroid; it is the third largest E-type after 44 Nysa and 55 Pandora, and has an exceptionally high albedo. As of 1991, it is thought to have an average radius of about 30 kilometers (19 mi). Back when asteroids were generally assumed to have low albedos, Angelina was thought to be the largest of this class, but modern research has
170 Maria is a Main belt asteroid. It is an S-type asteroid.
It is the namesake of the Maria asteroid family.
It was discovered by J. Perrotin on January 10, 1877. Its orbit was computed by Antonio Abetti, and the asteroid was named after his sister, Maria.
An occultation of a star by Maria was observed from Manitoba, Canada, on June 10, 1997.
19 Fortuna is one of the largest main-belt asteroids. It has a composition similar to 1 Ceres: a darkly colored surface that is heavily space-weathered with the composition of primitive organic compounds, including tholins.
Fortuna is 225 km in diameter and has one of the darkest known geometric albedos for an asteroid over 150 km in diameter. Its albedo has been measured at 0.028 and 0.037.
The Hubble Space Telescope observed Fortuna in 1993. It was resolved with an apparent diameter of 0.20 arcseconds (4.5 pixels in the Planetary Camera) and its shape was found to be nearly spherical. Satellites were searched for but none were detected.
Stellar occultations by Fortuna have been observed several times. Fortuna has been studied by radar.
It was discovered by J. R. Hind on August 22, 1852 and named after Fortuna, the Roman goddess of luck.
Fortuna has been perturbed by the 80 km 135 Hertha and was initially estimated by Baer to have a mass of 1.08×10 kg. A more recent estimate by Baer suggests it has a mass of 1.27×10 kg.
On December 21, 2012 Fortuna (~200 km) will harmlessly pass within 6.5Gm of asteroid 687 Tinette.
(4197) 1982 TA was discovered on October 11, 1982, by Eleanor F. Helin and Eugene Shoemaker. It is an Apollo, Mars- and Venus-crosser asteroid, only 1.7 km in diameter.
In 1996, astronomers at the Goldstone Observatory analysed it using radar delay-Doppler imaging. The resultant images are not very clear, but they show that (4197) 1982 TA has a roughly triangular shape, and a 3-hour rotation period.
5 Astraea is a large main-belt asteroid. Its surface is highly reflective (bright) and its composition is probably a mixture of nickel-iron with magnesium- and iron-silicates.
Astraea was the fifth asteroid discovered, on December 8, 1845, by K. L. Hencke and named for Astræa, a goddess of justice named after the stars. It was his first of two asteroid discoveries. The second was 6 Hebe. An amateur astronomer and post office employee, Hencke was looking for 4 Vesta when he stumbled on Astraea. The King of Prussia awarded him an annual pension of 1,200 marks for the discovery.
Photometry indicates prograde rotation, that the north pole points in the direction of right ascension 9 h 52 min, declination 73° with a 5° uncertainty. This gives an axial tilt of about 33°.
Astraea is physically unremarkable but notable mainly because for 38 years (after the discovery of Vesta in 1807) it had been thought that there were only four asteroids. In terms of maximum brightness, it is indeed only the seventeenth brightest main-belt asteroid, being fainter than 192 Nausikaa and even, at rare near-perihelion oppositions, the highly eccentric carbonaceous 324 Bamberga. It will be at magnitude +8.7
511 Davida is a large main-belt C-type asteroid. It was discovered by R. S. Dugan in 1903. It is one of the ten most massive asteroids. It is approximately 270–310 km in diameter and comprises an estimated 1.5% of the total mass of the asteroid belt. It is a C-type asteroid, which means that it is dark in colouring with a carbonaceous chondrite composition.
Davida is one of the few main-belt asteroids whose shape has been determined by ground-based visual observation. From 2002 to 2007, astronomers at the Keck Observatory used the Keck II telescope, which is fitted with adaptive optics, to photograph Davida. The asteroid is not a dwarf planet: there are at least two promontories and at least one flat facet with 15-km deviations from a best-fit ellipsoid. The facet is presumably a 150-km global-scale crater like the ones seen on 253 Mathilde. Conrad et al. (2007) show that craters of this size "can be expected from the impactor size distribution, without likelihood of catastrophic disruption of Davida."
Davida is named after David Peck Todd, an astronomy professor at Amherst College.
In 2001, Michalak estimated Davida to have a mass of (6.64±0.56)×10 kg In 2007, Baer and Chesley
9996 ANS is a C-type main belt asteroid. It orbits the Sun once every 4.68 years.
Discovered on October 17, 1960 by C. J. van Houten and I. van Houten-Groeneveld on archived photographic plates made by T. Gehrels, it was given the provisional designation 9070 P-L. It was later renamed in honour of the Astronomical Netherlands Satellite, an X-ray and gamma ray telescope located in space.
Pallas, formally designated 2 Pallas, is the second asteroid to have been discovered (after Ceres), and one of the largest in the Solar System. It is estimated to comprise 7% of the mass of the asteroid belt, and its diameter of 544 kilometres (338 mi) is slightly larger than that of 4 Vesta. It is however 10–30% less massive than Vesta, placing it third among the asteroids. It is possibly the largest irregularly shaped body in the Solar System (that is, the largest body not rounded under its own gravity), and a remnant protoplanet.
When Pallas was discovered by astronomer Heinrich Wilhelm Matthäus Olbers on March 28, 1802, it was counted as a planet, as were other asteroids in the early 19th century. The discovery of many more asteroids after 1845 eventually led to their re-classification.
The Palladian surface appears to be a silicate material; the surface spectrum and estimated density resemble carbonaceous chondrite meteorites. The Palladian orbit, at 34.8°, is unusually highly inclined to the plane of the asteroid belt, and the orbital eccentricity is nearly as large as that of Pluto, making Pallas relatively inaccessible to spacecraft.
2 Pallas is named after Pallas Athena,
90 Antiope ( /ænˈtaɪ.əpiː/ an-TY-ə-pee) is a double asteroid in the outer asteroid belt. It was discovered on October 1, 1866, by Robert Luther. In 2000 it was found to consist of two almost-equally-sized bodies orbiting each other. At average diameters of about 88 km and 84 km, both components are among the 500 largest asteroids. Antiope is part of the Themis family.
The number in 90 Antiope's name denotes that it was the 90th asteroid to be discovered. Its proper name comes from Greek mythology, though it is disputed as to whether this is Antiope the Amazon or Antiope the mother of Amphion and Zethus.
Since the discovery of Antiope's binary nature, the name "Antiope" technically refers to the slightly larger of the two components, with the smaller component bearing the provisional designation S/2000 (90) 1. However, the name "Antiope" is also used to refer to the binary system as a whole.
The most remarkable feature of Antiope is that it consists of two components of almost equal size (the difference in mass is less than 2.5%), making it a truly "double" asteroid. Its binary nature was discovered on 10 August 2000 by a group of astronomers using adaptive optics at the Keck
9973 Szpilman (pronounced: Shpilman) is a main belt asteroid. It orbits the Sun once every 4.03 years.
Discovered on July 12, 1993 by E. W. Elst working at the European Southern Observatory, it was given the provisional designation 1993 NB2. It was later renamed "Szpilman" after Wladyslaw Szpilman, a Polish pianist.
9994 Grotius is a main belt asteroid. It orbits the Sun once every 4.15 years.
Discovered on September 24, 1960 by C. J. van Houten and I. van Houten-Groeneveld on photographic plates made by T. Gehrels, it was given the provisional designation 4028 P-L. It was later renamed 9994 Grotius, to honour Hugo Grotius.
(9966) 1992 ES13 is a main belt asteroid. It orbits the Sun once every 3.67 years.
Discovered on March 2, 1992 by the Uppsala-ESO Survey of Asteroids and Comets, it was given the provisional designation "1992 ES13".
47 Aglaja ( /əˈɡlaɪ.ə/) is a large, dark main belt asteroid. It was discovered by Robert Luther on September 15, 1857 from Düsseldorf. The name was chosen by the Philosophical Faculty of the University of Bonn and refers to Aglaea, one of the Charites in Greek mythology.
The asteroid 12306 Pebronstein is a main belt asteroid discovered by Charles de Saint-Aignan at Lowell Observatory, examining films taken at Palomar.
Peter Bronstein (b. 1947) is father in-law of the discoverer. An avid sailor, Bronstein is always happy to share his time and his boat with others †
This orbital diagram is courtesy of the JPL Small-Body Database Browser
The asteroid 12374 Rakhat is a Main belt asteroid discovered by Charles de Saint-Aignan at Lowell Observatory, examining films taken at Palomar.
Rakhat is a planet with the first known extraterrestrial life in the novel The Sparrow, by Mary Doria Russell. First contact is established when a group of specialists organized by Jesuits is sent to the planet. †.
This orbital diagram is courtesy of the JPL Small-Body Database Browser
13 Egeria is a large main-belt G-type asteroid.
It was discovered by A. de Gasparis on November 2, 1850.
Egeria occulted a star on January 8, 1992. Its disc was determined to be quite circular (217×196 km). On January 22, 2008, it occulted another star, and this occultation was timed by several observers in New Mexico and Arizona, coordinated by the IOTA Asteroid Occultation Program. The result showed that Egeria presented an approximately circular profile to Earth of 214.8x192 km, well in agreement with the 1992 occultation. It has also been studied by radar.
Spectral analysis of Egeria shows it to be unusually high in water content, between 10.5-11.5% water by mass. This makes Egeria a prominent candidate for future water-mining ventures.
Egeria was named by Urbain J. J. Le Verrier, whose computations led to the discovery of Neptune, after the mythological nymph Egeria of Aricia, Italy, the wife of Numa Pompilius, second king of Rome.
1862 Apollo ( /əˈpɒloʊ/) is a Q-type asteroid, discovered by Karl Reinmuth in 1932, but lost and not recovered until 1973. It is named after the Greek god Apollo.
It is the namesake of the Apollo asteroids, and the first one discovered, although because it was lost for a time its asteroid number (1862) is higher than that of some other Apollo asteroids such as 1566 Icarus. Analysis of the spin of this object provided observational evidence of the YORP effect.
It was the first asteroid recognized to cross Earth's orbit. It is also a Venus- and Mars-crosser asteroid.
On November 4, 2005, it was announced that an asteroid moon, or satellite of Apollo, had been detected by radar observations from Arecibo Observatory, Puerto Rico, October 29 – November 2, 2005. The standard provisional designation for this satellite is S/2005 (1862) 1. The announcement is contained in the International Astronomical Union Circular (IAUC) 8627 . The satellite is just 80 m across and orbits Apollo closely, in an orbit a mere 3 km in radius .
2011 MD is an Apollo asteroid that passed relatively close to Earth's surface — at a distance of about 12,000 kilometers (7,500 mi), roughly the diameter of the Earth — at around 17:00 UTC (13:00 EDT) on June 27, 2011. Although the object was initially believed to be space junk, subsequent observations confirmed that it is an asteroid.
A few hours before the asteroid's nearest approach in 2011, it appeared close to the Sun, so observations were possible for only a brief period. Backyard astronomers were able to observe it with telescopes from Australia, southern Africa, and the Americas.
The asteroid was discovered on June 22, 2011, by the Lincoln Near-Earth Asteroid Research (LINEAR) pair of robotic telescopes in New Mexico, and according to original rough estimates, the asteroid's length was between 10 and 45 meters (30 and 150 ft). But based on the more recent absolute magnitude (H) of 28.1, the asteroid would be closer to 7 to 15 meters in diameter.
Emily Baldwin of Astronomy Now said that there was no threat of collision, and should the asteroid enter Earth's atmosphere, it would "mostly burn up in a brilliant fireball, possibly scattering a few meteorites", causing no likely
29 Amphitrite is one of the largest S-type asteroids, probably third in diameter after Eunomia and Juno, although Iris and Herculina are similar in size.
Amphitrite was discovered by Albert Marth on March 1, 1854, at the private South Villa Observatory, in Regent's Park, London. It was Marth's only asteroid discovery. Its name was chosen by George Bishop, the owner of the observatory, who named it after Amphitrite, a sea goddess in Greek mythology.
Amphirite's orbit is less eccentric and inclined than those of its larger cousins; indeed, it is the most circular of any asteroid discovered up to that point. As a consequence, it never becomes as bright as Iris or Hebe, especially as it is much further from the Sun than those asteroids. It can reach magnitudes of around +8.6 at a favorable opposition, but usually is around the binocular limit of +9.5.
In 2007, James Baer and Steven R. Chesley estimated Amphitrite to have a mass of 1.9×10 kg. A more recent estimate by Baer suggests it has a mass of 1.18×10 kg.
A satellite of the asteroid is suspected to exist, based on lightcurve data collected by Edward F. Tedesco.
50 Virginia ( /vərˈdʒɪnjə/) is a large, very dark main belt asteroid. It was discovered by James Ferguson on October 4, 1857 from the United States Naval Observatory in Washington, D.C.. Robert Luther discovered it independently on October 19 from Düsseldorf, and his discovery was announced first.
The reason for Virginia's name is not known; it may be named after Verginia, the Roman noblewoman slain by her father, but it may alternatively have been named after the American state of Virginia, which is contiguous with Washington.
Virginia has been studied by radar.
(55637) 2002 UX25 is a Spitzer dwarf-planet candidate that orbits the Sun in the Kuiper belt beyond Neptune. It takes roughly 280 years to orbit the Sun, and it has one known moon.
It is a trans-Neptunian object with an absolute magnitude of 3.6, making it a dwarf planet candidate. The Spitzer Space Telescope estimates it to be about 681 km in diameter. It was discovered on October 30, 2002, by the Spacewatch program. It is a mid-sized cubewano similar to (20000) Varuna.
A variability of the visual brightness was detected which could be fit to a period of 14.38 or 16.78 h (depending on a single-peaked or double peaked curve).
The Spitzer Space Telescope has estimated it to have a size of 681 +116
−114 km. It is redder than Varuna, unlike its neutral-colored "twin" 2002 TX300, in spite of similar brightness and orbit elements.
The discovery of a satellite of 2002 UX25 was reported in IAUC 8812 on 22 February 2007. The satellite was detected using the Hubble Space Telescope in August 2005. The orbit of this satellite has yet to be determined. The satellite was found at 0.16 arcsec from the primary with an apparent magnitude difference of 2.5. Assuming a similar albedo the magnitude
1000 Piazzia, discovered in 1923, is a main-belt asteroid orbiting the Sun. It was the 1000th minor planet to be numbered, and was named in honour of Giuseppe Piazzi, who discovered the first asteroid, 1 Ceres.
Its radius is estimated to be 24 km, and measurements of its light curve by Robert D. Stephens in 2001 showed it to be rotating with a period of 9.47 hours.
The planet Piazzia comes closest to is Mars. It draws nearer than 1.33 AU eleven times in the 20th and 21st centuries. Rarely, the two are closer than one AU. This last happened in 1638, and won't happen again for another 14,000 years.
2002 AA29 (also written 2002 AA29) is a small near-Earth asteroid that was discovered on January 9, 2002 by the LINEAR (Lincoln Near Earth Asteroid Research) automatic sky survey. The diameter of the asteroid is only about 50 to 110 metres (160 to 360 feet). It revolves about the Sun on an almost circular orbit very similar to that of the Earth. This lies for the most part inside the Earth's orbit, which it crosses near the asteroid's furthest point from the Sun, the aphelion. Because of this orbit, the asteroid is classified as Aten type, named after the asteroid (2062) Aten.
A further characteristic is that its mean orbital period about the Sun is exactly one sidereal year. This means that it is locked into a relationship with the Earth, since such an orbit is only stable under particular conditions. As yet only a few asteroids of this sort are known, locked into a 1:1 resonance with the Earth. The first was (3753) Cruithne, discovered in 1986.
Asteroids that have a 1:1 orbital resonance with a planet are also called co-orbital objects, because they follow the orbit of the planet. The most numerous known co-orbital asteroids are the so-called Trojans, which occupy the L4 and L5
2060 Chiron is a minor planet in the outer Solar System. Discovered in 1977 by Charles T. Kowal (precovery images have been found as far back as 1895), it was the first-known member of a new class of objects now known as centaurs, with an orbit between Saturn and Uranus.
Although it was initially called an asteroid and classified as a minor planet, it was later found to exhibit behavior typical of a comet. Today it is classified as both, and accordingly it is also known by the cometary designation 95P/Chiron.
Chiron is named after the centaur Chiron in Greek mythology. It should not be confused with the Plutonian moon Charon, discovered the following year, in 1978.
Mike Brown lists it as a possible dwarf planet with a measured diameter of 233 km.
Chiron was discovered on 18 October 1977 by Charles Kowal from images taken two weeks earlier at Palomar Observatory. It was given the temporary designation of 1977 UB. It was found near aphelion and at the time of discovery it was the most distant known minor planet. Chiron was even claimed as the tenth planet by the press. Chiron was later found on several precovery images, going back to 1895, which allowed its orbit to be accurately
Juno, formal designation 3 Juno in the Minor Planet Center catalogue system, was the third asteroid to be discovered and is one of the larger main-belt asteroids, being one of the two largest stony (S-type) asteroids, along with 15 Eunomia. It is estimated to contain 1% of the total mass of the asteroid belt. Juno was discovered on September 1, 1804, by German astronomer Karl L. Harding.
3 Juno is named after the mythological Jūno, the highest Roman goddess. The adjectival form is Junonian (jūnōnius).
With two exceptions, 'Juno' is the international name, subject to local variation: Italian Giunone, French Junon, Russian Yunona, etc. Its planetary symbol is ③. An older symbol, still occasionally seen, is ⚵ ().
Juno is one of the larger asteroids, perhaps tenth by size and containing approximately 1.0% the mass of the entire asteroid belt. It is the second-most-massive S-type asteroid after 15 Eunomia. Though one of the most massive asteroids, Juno has only 3% the mass of Ceres.
Amongst S-type asteroids, Juno is unusually reflective, which may be indicative of distinct surface properties. This high albedo explains its relatively high apparent magnitude for a small object not near
45 Eugenia is a large main-belt asteroid. It is famed as one of the first asteroids to be found to have a moon orbiting it. It is also the second known triple asteroid, after 87 Sylvia.
Eugenia was discovered on June 28, 1857 by the Franco-German amateur astronomer Hermann Goldschmidt. His instrument of discovery was a 4-inch aperture telescope located in his sixth floor apartment in the Latin Quarter of Paris. It was the forty-fifth minor planet to be discovered. The preliminary orbital elements were computed by Wilhelm Forster in Berlin, based on three observations in July, 1857.
The asteroid was named by its discoverer after Empress Eugenia di Montijo, the wife of Napoleon III. It was the first asteroid to be definitely named after a real person, rather than a figure from classical legend, although there was some controversy about whether 12 Victoria was really named for the mythological figure or for Queen Victoria.
Eugenia is a large asteroid, with a diameter of 214 km. It is an F-type asteroid, which means that it is very dark in colouring (darker than soot) with a carbonaceous composition. Like Mathilde, its density appears to be unusually low, indicating that it may be a
69230 Hermes is an Apollo, Mars- and Venus-crosser asteroid that passed Earth at about twice the distance of the Moon on October 30, 1937. It is named after the Greek god Hermes.
At the time, this was the closest known approach of an asteroid to the Earth. Not until 1989 was a closer approach (by 4581 Asclepius) observed. At closest approach, Hermes was moving 5° per hour across the sky and reached 8th magnitude.
It was discovered by Karl Reinmuth in images taken on October 28, 1937. Only four days of observations could be made before Hermes became too faint to be seen in the telescopes of the day. This was not enough to calculate an orbit, and Hermes was "lost" (see lost asteroids). It thus did not receive a number, but Reinmuth nevertheless named it after the Greek god Hermes. It was the only unnumbered but named asteroid, having only the provisional designation 1937 UB.
On October 15, 2003, Brian A. Skiff of the LONEOS project made an asteroid observation that, when the orbit was calculated backwards in time (by Timothy B. Spahr, Steven Chesley and Paul Chodas), turned out to be a rediscovery of Hermes. The orbit is now well known, and Hermes has been assigned sequential number
77185 Cherryh is a main belt asteroid. Its provisional designation was 2001 FE9.
It was discovered on March 20, 2001 at the George Observatory in Needville, Texas by amateur astronomers Don Wells and Alex Cruz of the Fort Bend Astronomy Club (FBAC) Asteroid Discovery Team. The discovery was confirmed the next night by Keith Rivich of the FBAC.
The asteroid was named by Wells and Cruz after the award winning American science fiction and fantasy author C. J. Cherryh.
9941 Iguanodon is an S-type main belt asteroid which orbits the Sun every 3.49 years.
It was discovered on February 4, 1989 by Eric Elst at the European Southern Observatory and given the provisional designation "1989 CB3". It was later renamed "Iguanodon" after the dinosaur genus Iguanodon.
5335 Damocles ( /ˈdæməkliːz/ DAM-ə-kleez) is the archetype of the Damocloids, asteroids that are inactive nuclei of the Halley Family and long-period comets. It was discovered in 1991 and named after Damocles, a figure of Greek mythology.
When Damocles was discovered, in 1991 by Robert H. McNaught, it was found to be on an orbit completely different from all others known. Damocles's orbit reached from inside the aphelion of Mars to as far as Uranus. It seemed to be in transition from a near-circular outer Solar System orbit to an eccentric orbit taking it to the inner Solar System. Duncan Steel, Gerhard Hahn, Mark Bailey, and David Asher carried out projections of its long-term dynamical evolution, and found a good probability that it will become an Earth-crosser asteroid, and may spend a quarter of its life in such an orbit. Damocles has a stable orbit for tens of thousands of years before and after the present, because its highly inclined orbit does not take it near Jupiter or Saturn.
There is some speculation that 5335 Damocles may have a meteor shower associated with it on Mars from the direction of Draco.
The adjectival form is Damoclean, /dæməˈkliːən/.
3362 Khufu is a near-Earth asteroid. It was discovered by R. Scott Dunbar and Maria A. Barucci at the Palomar Observatory in San Diego County, California, on August 30, 1984. Its provisional designation was 1984 QA. It is named after Khufu, an ancient Egyptian pharaoh.
Khufu crosses the orbits of Mars, Earth, and Venus and makes close approaches to Mercury as well. From 1900 to 2100 it drew nearer than 30 Gm (0.2 AU) to Mercury 26, Venus 27, Earth 20, and Mars 11 times.
52 Europa is one of the larger asteroids in the asteroid belt, having a diameter of 300 km. It was discovered on February 4, 1858, by Hermann Goldschmidt from his balcony in Paris. It is named after Europa, one of Zeus's conquests in Greek mythology, a name it shares with Jupiter's moon Europa.
Europa is approximately the seventh largest asteroid by volume. However, it has a low density (i.e. is highly porous), presumably through having suffered a particularly severe collision. In 2001, Michalak estimated Europa to have a mass of (5.2±1.8)×10 kg. In 2007, James Baer and Steven R. Chesley estimated Europa to have a mass of (1.9±0.4)×10 kg. A more recent estimate by Baer suggests it has a mass of 1.65×10 kg.
Europa is a very dark carbonaceous C-type, and is the fourth largest of this group. Spectroscopic studies have found evidence of olivines and pyroxenes on the surface, and there is some indication that there may be compositional differences between different regions It orbits close to the Hygiea asteroid family, but is not a member.
Lightcurve data for Europa has been particularly tricky to interpret, so much so that for a long time its period of rotation was in dispute (ranging
54 Alexandra is a very large and dark main-belt asteroid. It was discovered by Hermann Goldschmidt on September 10, 1858, and named after the German explorer Alexander von Humboldt; it was the first asteroid to be named after a male.
On May 17, 2005, this asteroid occulted a faint star (magnitude 8.5) and the event was observed and timed in a number of locations within the U.S. and Mexico. As a result a silhouette profile was produced, yielding a roughly oval cross-section with dimensions of 160 × 135 km (± 1 km).
Alexandra has been studied by radar.
The asteroid 8371 Goven is a Main belt asteroid discovered by Charles de Saint-Aignan at Lowell Observatory, examining films taken at Palomar.
The village of Goven in Brittany is the home of the Bernardinis, who were an extraordinary host family for the discoverer during his year-long stay there. Jean-Paul Bernardini served as a navigator in the French Marine during the 1960s, frequently practising the dying art of celestial navigation †.
This orbital diagram is courtesy of the JPL Small-Body Database Browser
(29075) 1950 DA is a near-Earth asteroid. It is notable for having the highest known probability of impacting Earth (between 0 and 0.33%). It has the highest Palermo rating with a value of 0.17 for a possible collision in the year 2880. For a brief period in late December 2004, asteroid 99942 Apophis held the record for Palermo scale values, with a value of 1.10.
1950 DA was first discovered on February 23, 1950, by Carl A. Wirtanen at Lick Observatory. It was observed for seventeen days and then lost because the short observation arc resulted in large uncertainties in Wirtanen's orbital solution. On 31 December 2000, it was recovered as 2000 YK66 and 2 hours later was recognized as 1950 DA.
On March 5, 2001, 1950 DA made a close approach to the Earth of 0.0520726 AU (7,789,950 km; 4,840,450 mi). It was studied by radar at the Goldstone and Arecibo observatories from March 3 to 7 2001.
The studies showed that the asteroid has a mean diameter of 1.1–1.4 km (3,600-4,600 ft). Optical lightcurve analysis by Lenka Sarounova and Petr Pravec shows that its rotation period is 2.1216 ± 0.0001 hours. Due to its short rotation period and high radar albedo, 1950 DA is thought to be fairly
38 Leda ( /ˈliːdə/) is a large, dark main-belt asteroid.
It was discovered by J. Chacornac on January 12, 1856, and named after Leda, the mother of Helen of Troy in Greek mythology.
Leda is also the name of a satellite of Jupiter and a catalogue of galaxies.
Leda has been studied by radar.
(15760) 1992 QB1, also written (15760) 1992 QB1, was the first trans-Neptunian object to be discovered after Pluto and Charon. It was discovered in 1992 by David C. Jewitt and Jane X. Luu at the Mauna Kea Observatory, Hawaii. It is now classed as a classical Kuiper belt object, and gave rise to the name cubewano for this kind of object, after the "QB1" portion of its designation. Decoding its provisional designation, "QB1" reveals that it was the 27th object found in the second half of August of that year. Over 1,000 further objects have been found beyond Neptune, a good number of which are classical Kuiper belt objects.
The discoverers suggested the name "Smiley" for (15760) 1992 QB1, but the name was already used for an asteroid 1613 Smiley, named after the American astronomer Charles Hugh Smiley. It has received the number 15760, and remains unnamed; it is normally referred to simply as "QB1", even though this is technically ambiguous without the year of discovery.
25143 Itokawa ( /ˌiːtoʊˈkɑːwə/; Japanese: イトカワ [itokawa]) is an Apollo and Mars-crosser asteroid. It was the first asteroid to be the target of a sample return mission, the Japanese space probe Hayabusa.
The asteroid was discovered in 1998 by the LINEAR project and was given the provisional designation 1998 SF36. In August 2003, it was officially named after Hideo Itokawa, a Japanese rocket scientist.
Itokawa is an S-type asteroid. Radar imaging by Goldstone in 2001 observed an ellipsoid 630 ± 60 m long and 250 ± 30 m wide.
The Hayabusa mission confirmed these findings and also suggested that Itokawa may be a contact binary formed by two or more smaller asteroids that have gravitated toward each other and stuck together. The Hayabusa images show a surprising lack of impact craters and a very rough surface studded with boulders, described by the mission team as a 'rubble pile'. Furthermore, the density of the asteroid is too low for it to be made from solid rock. This would mean that Itokawa is not a monolith but rather a ‘rubble pile’ formed from fragments that have cohered over time.
Shape from Goldstone and Arecibo Radars (Itokawa).
In 2000, it was selected as the target of
44 Nysa ( /ˈnaɪsə/) is a large and very bright main-belt asteroid, and the brightest member of the Nysian asteroid family. It is classified as a rare class E asteroid and is probably the largest of this type (though 55 Pandora is only slightly smaller).
It was discovered by Hermann Goldschmidt on May 27, 1857, and named after the mythical land of Nysa in Greek mythology.
In 2002 Kaasalainen et al. used 63 lightcurves from the Uppsala Asteroid Photometric Catalog (UAPC) to construct a shape model of 44 Nysa. The shape model is conical, which they interpreted as indicating the asteroid may actually be a contact binary.
In 2003, Tanga et al. published results obtained from the Fine Guidance Sensor on the Hubble Space Telescope in which high-precision interferometry was performed on Nysa with the goal of a more accurate shape determination. Due to Hubble's orbit around the Earth, hours-long photometry sessions, as are normally used to resolve the asteroid's shape, were not possible. Instead the team used interferometry on the asteroid at the time in its rotation when it would have its longest axis perpendicular to the Earth. Ellipsoidal shape models were then fit to the resulting data
62 Erato ( /ɨˈreɪtoʊ/ i-RAY-toh) is a large and dark, probably carbonaceous Themistian asteroid. It is a member of the Eos family.
Erato is the first asteroid to have been credited with co-discoverers, Oskar Lesser and Wilhelm Forster, who discovered it on September 14, 1860 from the Berlin Observatory. It was their first and only asteroid discovery. The name was chosen by Johann Franz Encke, director of the observatory, and refers to Erato, the Muse of lyric poetry in Greek mythology.
8379 Straczynski (provisional designation 1992 SW10) is an asteroid discovered on September 27, 1992 at the Kitt Peak National Observatory by the Spacewatch project. It was named in honour of science fiction writer J. Michael Straczynski, creator of the television series Babylon 5.
9995 Alouette is an S-type main belt asteroid. It orbits the Sun once every 3.69 years.
Discovered on September 24, 1960 by C. J. van Houten and I. van Houten-Groeneveld on archived photographic plates made by T. Gehrels, it was given the provisional designation 4805 P-L. It was later renamed Alouette in honour of Alouette-1, the first Canadian satellite.
1685 Toro is an Apollo asteroid that orbits the Sun in an 5:8 resonance with Earth, and a near 5:13 resonance with Venus. Because of this unusual orbit, it is sometimes referenced as "Earth's second satellite".
Toro was discovered by Carl A. Wirtanen at the Lick Observatory in 1948. It was the third Apollo asteroid to be discovered. The name honours Betulia Toro, wife of the astronomer Samuel Herrick. Herrick had studied the asteroid's orbit, and requested the name, along with that of 1580 Betulia.
Based on orbital paths, 1685 Toro is the best candidate for the source of the Sylacauga meteorite, the only meteorite known to have injured a human being, when it struck and bruised Mrs. Ann Hodges of Sylacauga, Alabama, on 30 November 1954.
1685 Toro is reported to be an S-type asteroid composed of L chondrite.
2009 VA is an asteroid that came within 14,000 kilometres (8,700 mi) of Earth on November 6, 2009 making it the 3rd closest non-impacting approach of a cataloged asteroid. With a diameter of only 7 metres (23 ft), scientists think that even if it had been on a direct collision course with Earth, it would have likely burned up in the atmosphere. The space rock made its pass by Earth just fifteen hours after its discovery.
The asteroid was first discovered by the Catalina Sky Survey at the University of Arizona. It was determined that the object would make a pass well within the orbit of the Moon, but would not strike the Earth. The object passed so close to the Earth that its trajectory through space was modified by Earth's gravity.
24 Themis is one of the largest main-belt asteroids. It is also the largest member of the Themistian asteroid family. It was discovered by Annibale de Gasparis on April 5, 1853. It is named after Themis, the personification of natural law and divine order in Greek mythology.
24 Themis was discovered on 5 April 1853 by Annibale de Gasparis of Naples, though it was given its name by fellow Italian astronomer Angelo Secchi. The asteroid was named after Themis, the Greek goddess of law. Gravitational perturbations in the orbit of Themis were used to calculate the mass of Jupiter as early as 1875.
On 24 December 1975, 24 Themis had a close encounter with 2296 Kugultinov with a minimum distance of 0.016 AU (2,400,000 km). By analyzing the perturbation of Kugultinov's orbit due to the gravitational pull of Themis, the mass of Themis was determined to be approximately 2.89×10 solar masses.
Themis is in an elliptical orbit around the Sun with an eccentricity of 0.1306 and an inclination of 0.76°. It has an orbital period of 5.54 years. The distance between Themis and the Sun ranges from 2.71 AU at perihelion and 3.55 AU at aphelion, with a mean distance of 3.1302 AU. Themis is part of the
7166 Kennedy is an asteroid which was discovered by Edward L. G. Bowell at the Anderson Mesa Station of the Lowell Observatory in Flagstaff, Arizona, on 10 October 1985. Initially designated 1985 TR, it was named on 8 August 1998 in memory of Malcolm Kennedy (1944-1997), Secretary of the Astronomical Society of Glasgow , who died in a road accident in Hungary, 18 November 1997, on a mercy mission carrying aid to eastern Europe. Born and raised in New Zealand, Kennedy became a civil engineer in Scotland. He was an energetic member of the Free Church in Cumbernauld, near Glasgow. As secretary of the ASG, he ensured that meetings ran smoothly, enlivening them with wordplay and puns.
(15788) 1993 SB is a trans-Neptunian object of the plutino class. Apart from Pluto, it was one of the first such objects discovered (beaten by two days by 1993 RO and by one day by 1993 RP), and the first to have an orbit calculated well enough to receive a number. The discovery was made in 1993 at the La Palma Observatory with the Isaac Newton Telescope. Very little is known about the object. Even the diameter estimate of ~130 km is based on an assumed albedo of 0.09.
(15875) 1996 TP66, also written as (15875) 1996 TP66, is a resonant trans-Neptunian object in 2:3 resonance with Neptune, like Pluto (plutino). It was discovered on October 11, 1996 by Chad Trujillo, David C. Jewitt, and Jane X. Luu at the Mauna Kea Observatory, Hawaii.
This plutino is currently 27 AU from the Sun, and came to perihelion (q=26.3 AU) in 2000. This means that this small plutino is currently well inside the orbit of the planet Neptune. Like Pluto, this plutino spends part of its orbit closer to the Sun than Neptune. Like all resonant trans-Neptunian objects its orbit is dominated by Neptune. Simulations by the Deep Ecliptic Survey (DES) show that over the next 10 million years 1996 TP66 can acquire a perihelion distance (qmin) as small as 25.9 AU.
Dwarf-planet candidate Huya and plutino (120216) 2004 EW95 are also currently inside the orbit of Neptune.
Calculations by the Minor Planet Center in 1997 showed that the eccentric orbit comes within 6.9 AU of Uranus and stays more than 22.6 AU from Neptune over a 14,000-year period centered on the present.
The size of 1996 TP66 was estimated by the Herschel Space Telescope to be 154.0+28.8
−33.7 km. The object has a very
(53319) 1999 JM8 (also written (53319) 1999 JM8) is a near-Earth asteroid and Mars-crosser asteroid discovered by LINEAR. Radar imaging by Goldstone and Arecibo has revealed the asteroid to be 3.5 km in diameter. Like the asteroid 4179 Toutatis, its rotation speed is unusually slow and possibly chaotic. Its shape is bizarre, and is vaguely reminiscent of a roast chicken.
It passed closer than 30 Gm to the Earth five times in the last century (5 Gm in 1990), but its closest approach in the 21st century will be at 38.3 Gm, in 2075.
9992 1997 TG19 is a Mars crossing asteroid. It orbits the Sun once every 3.20 years.
It was discovered on October 8, 1997 by Tetsuo Kagawa and Takeshi Urata at the Gekko Observatory, and given the provisional designation 1997 TG19.
10515 Old Joe is a main-belt asteroid discovered by Brian G. W. Manning on October 31, 1989 from Stakenbridge, in the village of Churchill, near Kidderminster, Worcestershire, England. It is named after the Joseph Chamberlain Memorial Clock Tower (nicknamed Old Joe) at the University of Birmingham.
The asteroid 12373 Lancearmstrong is a Main belt asteroid discovered by Charles de Saint-Aignan at Lowell Observatory, examining films taken at Palomar.
Lance Armstrong (b. 1971) is an American cyclist and cancer survivor. After being diagnosed with advanced testicular cancer in 1996, he was able to return to cycling and win the Tour de France a record seven consecutive times. He serves as an inspiration to cancer survivors and athletes around the world †.
This orbital diagram is courtesy of the JPL Small-Body Database Browser
14827 Hypnos (also known by its provisional designation 1986 JK) is an Apollo near-Earth asteroid (NEA) discovered by Carolyn S. Shoemaker and Eugene Merle Shoemaker at Palomar Observatory on May 5, 1986. It is named after Hypnos, the Greek god of sleep.
Hypnos may be the nucleus of an extinct comet that is covered by a crust several centimeters thick that prevents any remaining volatiles from outgassing. Hypnos is frequently perturbed by Jupiter.
In 1958, Hypnos passed less than 0.03 AU from both Earth and Mars. Neither planet has been approached so closely by Hypnos since the 862 pass of Earth, or will be until the 2214 pass of Earth.
It has a well determined orbit and has been observed 170 times since 1986.
The asteroid 1998 KY26 (also written 1998 KY26) was discovered on June 2, 1998, by Spacewatch and observed until June 8, when it passed 800,000 kilometers (half a million miles) away from Earth (a little more than twice the Earth-Moon distance). It is roughly spherical and is only about 30 metres (98 ft) in diameter. Although it is nearly small enough be classified a meteoroid, the most common definition uses a diameter of 10 m as the demarcation, just making 1998 KY26 an asteroid. Because of this, as all the other objects smaller than 1998 KY26 are under 10 meters in diameter, this makes 1998 KY26 the smallest asteroid, the largest being Ceres.
With a rotation period of 10.7 minutes it has one of the shortest sidereal days of any known object in the solar system, and cannot possibly be a rubble pile. It is also one of the most easily accessed objects in the solar system, and its orbit frequently brings it on a path very similar to the optimum Earth-Mars transfer orbit. This, coupled with the fact that it is water rich, makes it an attractive target for further study and a potential source of water for future missions to Mars.
The discovery is attributed to an international team of
2010 GA6 is a Near-Earth asteroid discovered in 2010. It is described as a relatively small space rock about 22 meters (72 ft) wide. It was discovered by astronomers with the Catalina Sky Survey in Tucson, Arizona. The asteroid passed by earth at a distance of about 223,000 miles at 7:06 pm EST on April 8, 2010. It was removed from the Sentry Risk Table on April 8, 2010.
2010 TD54 is a small asteroid-like object that was discovered in an orbit that crossed through the Earth-moon system. It made its closest approach at 10:51, 12 October 2010 UTC (6:51 EDT a.m.). NASA reported its size as about 5 to 10 metres in diameter, possessing an absolute magnitude of 28.799; its closest approach to Earth was about 45,000 kilometres, one of the closest known approaches of an asteroid to earth, at which time the object appeared about 14th magnitude. One of the Catalina Sky Survey telescopes north of Tucson, Arizona discovered it on 9 October 2010. It was removed from the Sentry Risk Table on 11 October 2010.
2062 Aten ( /ˈɑːtən/ AH-tən) is an asteroid that was discovered at the Palomar Mountain Observatory by Eleanor F. Helin, who is now the principal scientist for the NEAT (Near-Earth Asteroid Tracking) project. It is named after Aten, the Egyptian god of the solar disk.
Aten was the first asteroid found to have a semi-major orbital axis of less than one astronomical unit. A new category of asteroids was thus created, the Atens, of which 16 are known and numbered, and some 212 awaiting numbering as of July 2004, ranging from (99907) 1989 VA to 2004 MD6.
28 Bellona is a large main-belt asteroid. It was discovered by R. Luther on March 1, 1854, and named after Bellōna, the Roman goddess of war; the name was chosen to mark the beginning of the Crimean War.
Bellona has been studied by radar.
36 Atalante ( /ˌætəˈlæntiː/) is a large, dark main-belt asteroid. It was discovered by the German-French astronomer H. Goldschmidt on October 5, 1855, and named by French mathematician Urbain Le Verrier after the Greek mythological heroine Atalanta (of which Atalante is the German form).
Observation of the asteroid light curve indicates it is rotating with a period of 9.93 ± 0.01 hours. During this interval, the magnitude varies by an amplitude of 0.12 ± 0.02. By combining the results of multiple light curves, the approximate ellipsoidal shape of the object can be estimated. It appears to be slightly elongated, being about 28.2% longer along one axis compared to the other two. Atalante was observed by Arecibo radar in October 2010.
45300 Thewrewk (2000 AF45) is a main-belt asteroid discovered on January 1, 2000 by Krisztián Sárneczky and László Kiss at Piszkéstető Station a part of the Konkoly Obszervatórium in the Mátra Mountains of Hungary. It has an orbital period around the Sun of 5.45 Earth years.
55 Pandora is a fairly large and very bright asteroid in the asteroid belt. Pandora was discovered by George Mary Searle on September 10, 1858 from the Dudley Observatory near Albany, NY. It was his first and only asteroid discovery.
It is named after Pandora, the first woman in Greek mythology, who unwisely opened a box that released evil into the world. The name was apparently chosen by Blandina Dudley, widow of the founder of the Dudley Observatory, who had been involved in an acrimonious dispute with astronomer B. A. Gould. Gould felt that the name had an "apt significance". The asteroid shares its name with Pandora, a moon of Saturn.
Recent analysis has identified Pandora as the second-largest of the E-type asteroids, after 44 Nysa.
8405 Asbolus ( /ˈæzbɵləs/; from Greek: Άσβολος) is a centaur orbiting between the orbits of Jupiter and Neptune. It was discovered by James V. Scotti and Robert Jedicke of Spacewatch at Kitt Peak Observatory on April 5, 1995. It is named after Asbolus (Greek for sooty), a centaur in Greek mythology. Its provisional designation was 1995 GO.
Observations with the Spitzer Space Telescope in 2007 resulted in a diameter calculation of about 84 ± 8 km.
No resolved images of it have ever been made but, in 1998, spectral analysis of its composition by the Hubble Space Telescope revealed a fresh impact crater on its surface, less than 10 million years old. Centaurs are dark in colour, because their icy surfaces have darkened after long exposure to solar radiation and the solar wind. However, fresh craters excavate more reflective ice from below the surface, and that is what Hubble has detected on Asbolus.
Centaurs have short dynamical lifetimes due to perturbations by the giant planets. Asbolus is estimated to have an orbital half-life of about 860 kiloannum. Asbolus is currently classified as a SN centaur since Saturn is considered to control the perihelion and Neptune controls the
8710 Hawley is a Main belt asteroid discovered by Charles de Saint-Aignan at Lowell Observatory, examining films taken at Palomar.
Named in honor of the discoverer's friend and mentor, Walter N. Hawley, a physics and astronomy teacher at Saint Paul's School in Concord, New Hampshire. He is also the director of the Saint Paul's Astronomy Center, an observatory of unequaled quality at the high-school level. Hawley has observed the night sky with his students since 1972, acquainting them with such wonders as the Aurora Borealis and Messier Objects, as well as lesser wonders, such as Murphy's Law---and frostbite. †.
This orbital diagram is courtesy of the JPL Small-Body Database Browser
9962 Pfau is a main belt asteroid. It orbits the Sun once every 3.68 years.
Discovered on December 28, 1991 by F. Borngen, it was given the provisional designation "1991 YL1". It was later renamed "Pfau" after Werner Pfau, a former director of the Jena University Observatory and former chairman of the Astronomische Gesellschaft.
9969 Braille is a small Mars-crossing asteroid that orbits the Sun once every 3.58 years. It was discovered in 1992 by astronomers at Palomar observatory and later named after Louis Braille, the inventor of the writing system for the blind. It was photographed in closeup by the spacecraft Deep Space 1 in 1999, but a malfunction resulted in indistinct images.
Discovered on May 27, 1992, by E. F. Helin and K. J. Lawrence working at the Palomar observatory as part of NASA's Planet-Crossing Asteroid Survey, it was given the provisional designation 1992 KD. Later, it was renamed Braille in honour of Louis Braille as suggested by Kennedy Space Center software engineer Kerry Babcock in The Planetary Society's contest titled "Name That Asteroid".
Braille has an unusually inclined orbit, and belongs to the somewhat rare class of asteroids known as Mars-crossing asteroids. Simulations of its orbit by scientists of the Deep Space 1 project predict that it will evolve into an Earth-crossing orbit in about 4000 years. Although its closest approach to the Sun is closer than Mars orbit, its highly elliptical orbit takes it almost half-way to Jupiter at its apoapsis, and as such its semi-major
9985 Akiko is a main belt asteroid. It orbits the Sun once every 3.49 years.
Discovered by R. H. McNaught and H. Abe on May 12, 1996 it was given the provisional designation 1996 JF. It was later renamed 9985 Akiko after Akiko Yamamoto, a longtime collaborator with H. Abe.
99942 Apophis ( /əˈpɒfɪs/, previously known by its provisional designation 2004 MN4) is a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a small probability (up to 2.7%) that it would strike the Earth in 2029. Additional observations provided improved predictions that eliminated the possibility of an impact on Earth or the Moon in 2029. However, a possibility remained that during the 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole, a precise region in space no more than about a half-mile wide, that would set up a future impact on April 13, 2036. This possibility kept the asteroid at Level 1 on the Torino impact hazard scale until August 2006, when the probability that Apophis will pass through the keyhole was determined to be very small. Apophis broke the record for the highest level on the Torino Scale, being, for only a short time, a level 4, before it was lowered. Its diameter is approximately 270 meters (885 ft). As of October 7, 2009 (2009 -10-07), the probability of an April 13, 2036 impact is considered to be 1 in 250,000. Of objects not recently observed, there are 7
(243) Ida I Dactyl (pronounced /ˈdæktɨl/ dak'-tl) is a tiny asteroid moon (1.4 km in diameter) that orbits asteroid 243 Ida. It was imaged by the Galileo spacecraft on August 28, 1993; the Galileo mission member Ann Harch, while examining the delayed image downloads, discovered it on February 17, 1994. It was provisionally designated S/1993 (243) 1. The satellite was named after the mythical creatures called dactyls who lived on the Mount Ida according to the Greek mythology.
Dactyl orbits Ida with a period of 1.54 days at an average distance of 108 km, with an inclination of 9° to Ida's equator. The orbit is not very accurately known because Galileo coincidentally passed very nearly in its plane while taking the images.
The origins of Dactyl are unclear, but two main hypotheses exist. The first is that Dactyl and Ida formed at the same time, and the second is that Dactyl was knocked loose by a later impact. Both hypotheses have problems and cannot explain the situation satisfactorily.
Dactyl was the first asteroid moon discovered. The discovery settled the long debate over the existence of asteroid moons.