FANDOM


Ceres, formal designation 1 Ceres, is the smallest identified dwarf planet in the Solar System and the only one in the asteroid belt. It was discovered on January 1, 1801, by Giuseppe Piazzi,[1] and is named after the Roman goddess Ceres — the goddess of growing plants, the harvest, and motherly love.

With a diameter of about 950 km, Ceres is by far the largest and most massive body in the asteroid belt, and contains a third (32%) of the belt's total mass.[2][3] Recent observations have revealed that it is spherical, unlike the irregular shapes of smaller bodies with lower gravity.[4] The surface of Ceres is probably made of a mixture of water ice and various hydrated minerals like carbonates and clays.[5] Ceres appears to be differentiated into a rocky core and ice mantle.[6] It may harbour an ocean of liquid water underneath its surface, which makes it a potential target in the search for extraterrestrial life.[3]

Ceres' apparent magnitude ranges from 6.7 to 9.3, and hence at its brightest is still too dim to be seen with the naked eye.[7] On September 27, 2007, NASA launched the Dawn space probe to explore Vesta (2011–2012) and Ceres (2015).[8]

DiscoveryEdit

The idea that an unknown planet could exist between the orbits of Mars and Jupiter was first suggested by Johann Elert Bode in 1768.[1] His considerations were based on the so called Titius-Bode law, a now-abandoned theory which had been proposed by Johann Daniel Titius in 1766.[1][9] According to this law the semi-major axis of the planet should be near 2.8 AU.[9] William Herschel's discovery of Uranus in 1781[1] increased faith in the law of Titius and Bode, and in 1800, twenty-four experienced astronomers combined their efforts and began a methodical search for the proposed planet.[1][9] The group was headed by Franz Xaver von Zach, editor of the Monatliche Correspondenz. While they did not discover Ceres, they later found several large asteroids.[9]

File:Piazzi Cerere.jpg

Ceres was discovered on 1 January 1801, by Giuseppe Piazzi, who was searching for a star listed by Francis Wollaston as Mayer 87 because it was not in Mayer's zodiacal catalogue in the position given.[1] Instead of a star, Piazzi found a moving star-like object, which he first thought was a comet.[10] Piazzi observed Ceres a total of 24 times, the final time on February 11, when illness interrupted his observations. He announced his discovery on January 24, 1801 in letters to fellow astronomers, among them his compatriot Barnaba Oriani of Milan. He reported it as a comet but "since its movement is so slow and rather uniform, it has occurred to me several times that it might be something better than a comet".[1] In April, Piazzi sent his complete observations to Oriani, Johann Elert Bode, and Jérôme Lalande in Paris. The information was published in the September 1801 issue of the Monatliche Correspondenz.[10]

Soon after this, Ceres' apparent position had changed (mostly due to the Earth's orbital motion). It then appeared too close to the Sun's glare, so other astronomers could not confirm the observations of Piazzi until the end of the year. However after such a long time it was difficult to predict its exact position. To recover Ceres Carl Friedrich Gauss, then 24 years old, developed an efficient method of orbit determination.[10] In only a few weeks, he predicted its path, and sent his results to von Zach. On 31 December 1801, von Zach and Heinrich W. M. Olbers found Ceres near the predicted position and thus recovered it.[10]

In 1802 Herschel estimated Ceres to be 260 km in diameter, and in 1811 Johann Hieronymus Schröter estimated Ceres to be 2613 km in diameter.[11][12]

NameEdit

Piazzi originally suggested the name Ceres Ferdinandea (Ital­ian, Cerere Ferdinan­dea) for this body, after both the mythological figure Ceres (Roman goddess of plants) and King Ferdinand of Two Sicilies.[1][10] "Ferdinandea" was not acceptable to other nations of the world and was thus dropped. Ceres was also called Hera for a short time in Germany.[13] In Greece, it is called Δήμητρα (Demeter), after the goddess Ceres' Greek equivalent; in English usage, Demeter is the name of an asteroid (1108 Demeter). Due to its uncommon usage, there is no consensus as to the proper adjectival form of the name, although the nonce forms Cerian and Cerean[3] have been used in fiction. Etymologically, the form Cererean would be correct, derived from its Latin genitive, Cereris.[14] Ceres' astronomical symbol is a sickle, (Ceres symbol), similar to Venus' symbol (Venus symbol) which is the female gender symbol and Venus' hand mirror.[10][15] The element Cerium was named after Ceres.[16] The element Palladium was originally also named after Ceres, but the discoverer changed its name after Cerium was named. Palladium is named after asteroid 2 Pallas.[17]

StatusEdit

File:Ceres Earth Moon Comparison.png

The classification of Ceres has changed more than once and has been the subject of some disagreement. Johann Elert Bode believed Ceres to be the "missing planet" he had proposed to exist between Mars and Jupiter, at a distance of 419 million km (2.8 AU) from the Sun.[1] Ceres was assigned a planetary symbol, and remained listed as a planet in astronomy books and tables (along with 2 Pallas, 3 Juno and 4 Vesta) for about half a century until further asteroids were discovered.[1][10][18]

However, as other objects were discovered in the area it was realised that Ceres represented the first of a class of many similar bodies.[1] Sir William Herschel coined in 1802 the term asteroid ("star-like") for such bodies,[18] writing "they resemble small stars so much as hardly to be distinguished from them, even by very good telescopes".[19] As the first such body to be discovered, it was given the designation 1 Ceres under the modern system of asteroid numbering.[18]

The 2006 debate surrounding Pluto and what constitutes a 'planet' led to Ceres being considered for reclassification as a planet.[20][21] A proposal before the International Astronomical Union for the definition of a planet would have defined a planet as "a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet".[22] Had this resolution been adopted, it would have made Ceres the fifth planet in order from the Sun.[23] However, it was not accepted, and in its place an alternate definition of "planet" came into effect as of August 24, 2006: A planet is "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit." By this definition, Ceres is not a planet (because it shares its orbit with the thousands of other asteroids in the main belt), and is now classified as a "dwarf planet" (along with Pluto, Makemake, Haumea and Eris). The issue of whether Ceres remains an asteroid was not addressed.[24] Dual classifications such as main-belt comets do exist, and being a dwarf planet does not preclude having other designations.[25]

Physical characteristicsEdit

File:Moon and Asteroids 1 to 10.svg
File:Ceres Rotation.jpg

Ceres is the largest object in the asteroid belt, which lies between Mars and Jupiter.[5] The Kuiper belt is known to contain larger objects, including Pluto, 50000 Quaoar, and 90482 Orcus, while more distant Eris, in the scattered disc, is the largest of all these bodies.[26]

The mass of Ceres has been determined by analysis of the influence it exerts on small asteroids. Results obtained by different authors are slightly different.[27] The average of the three most precise values as of 2008 is approximately 9.4×1020 kg.[28][27] With this mass Ceres comprises about a third of the estimated total 3.0 ± 0.2 ×1021 kg mass of the asteroids in the solar system,[29] together totalling about four percent of the mass of the Moon. Ceres' size and mass are sufficient to give it a nearly spherical shape.[6] That is, it is close to hydrostatic equilibrium. In contrast, other large asteroids such as 2 Pallas,[30] 3 Juno,[31] 4 Vesta[32] and in particular 10 Hygiea[33] are known to be quite irregular.

Peter Thomas of Cornell University has proposed that Ceres has a differentiated interior;[6] its oblateness appears too small for an undifferentiated body, which indicates that it consists of a rocky core overlain with an icy mantle.[6] This 100 km-thick mantle (23–28 percent of Ceres by mass; 50 percent by volume[34]) contains 200 million cubic kilometres of water, which is more than the amount of fresh water on the Earth.[35] This result is supported by the observations made by the Keck telescope in 2002 and by evolutionary modelling.[28][36] Also, some characteristics of its surface and history (such as its distance from the Sun, which weakened solar radiation enough to allow some fairly low-freezing-point components to be incorporated during its formation), point to the presence of volatile materials in the interior of Ceres.[28]

SurfaceEdit

The surface composition of Ceres is broadly similar to that of C-type asteroids.[5] However, some differences do exist. The ubiquitous features in the IR spectra of Ceres are that of hydrated materials, which indicates the presence of significant amounts of water in the interior of this body. Other possible surface constituents include iron-rich clays (cronstedtite) and carbonates (dolomite and siderite), which are common minerals in carbonaceous chondrite meteorites.[5] The spectral features of carbonates and clay are usually absent in the spectra of other C-type asteroids.[5] Sometimes Ceres is classified as G-type asteroid.[37]

The surface of Ceres is relatively warm. The maximum temperature with the Sun overhead was estimated from measurements to be 235 K (about −38 °C) on May 5, 1991.[38] Taking into account also the heliocentric distance at the time, this gives an estimated maximum of about 239 K at perihelion.

File:Ceres Cutaway.jpg

Only a few features have been unambiguously detected on the surface of Ceres. High resolution ultraviolet Hubble Space Telescope images taken in 1995 showed a dark spot on its surface which was nicknamed "Piazzi" in honour of the discoverer of Ceres.[37] This was thought to be a crater. Later near-infrared images with a higher resolution taken over a whole rotation with the Keck telescope using adaptive optics showed several bright and dark features moving with the dwarf planet's rotation.[28][39] Two dark features had circular shapes and are presumably craters; one of them was observed to have a bright central region, while another was identified as the "Piazzi" feature.[28][39] More recent visible light Hubble Space Telescope images of a full rotation taken in 2003 and 2004 showed 11 recognizable surface features, the nature of which are currently unknown.[4][40] One of these features corresponds to the "Piazzi" feature observed earlier.[4]

These last observations also determined that Ceres' north pole points in the direction of right ascension 19 h 24 min (291°), declination +59°, in the constellation Draco. This means that Ceres' axial tilt is very small—about 3°.[6][4]

AtmosphereEdit

There are indications that Ceres may have a tenuous atmosphere and water frost on the surface.[41] Surface water ice is not stable at distances less than 5 AU from the Sun,[42] so it is expected to sublimate if is exposed directly to solar radiation. Water ice can migrate from the deep layers of Ceres to the surface, but will escape in a very short time. As a result, it is difficult to detect water vaporization. Water escaping from Ceres's polar regions was possibly observed in the early 90s but this has not been unambiguously proven. It may be possible to detect escaping water from the surroundings of a fresh impact crater or from cracks in the sub-surface layers of Ceres.[28] Ultraviolet observations by IUE spacecraft detected statistically significant hydroxide water vapour near the Cererean north pole.[41]

OrbitEdit

File:Ceres Orbit.svg

Ceres follows an orbit between Mars and Jupiter, within the main asteroid belt, with a period of 4.6 Earth years. The orbit is moderately inclined (i = 10.6° compared to 7° for Mercury and 17° for Pluto) and moderately eccentric (e = 0.08 compared to 0.09 for Mars).[43]

The diagram illustrates the orbits of Ceres (blue) and several planets (white/grey). The segments of orbits below the ecliptic are plotted in darker colours, and the orange plus sign is the Sun's location. The top left diagram is a polar view that shows the location of Ceres in the gap between Mars and Jupiter. The top right is a close-up demonstrating the locations of the perihelia (q) and aphelia (Q) of Ceres and Mars. The perihelion of Mars is on the opposite side of the Sun from those of Ceres and several of the large main belt asteroids, including 2 Pallas and 10 Hygiea. The bottom diagram is a perspective view showing the inclination of the orbit of Ceres compared to the orbits of Mars and Jupiter.

In the past, Ceres had been considered to be the largest member of an asteroid family.[44] These groupings of asteroids share similar orbital elements, which may indicate a common origin through an asteroid collision some time in the past. Ceres, however, was found to have spectral properties different from other members of the family, and so this grouping is now called the Gefion family, named after the lowest-numbered family member, 1272 Gefion.[44] Ceres appears to be merely an interloper in its own family, coincidentally having similar orbital elements but not a common origin.[45] The rotational period of Ceres is 9 hours and 4 minutes.[46]

Transits of planets from CeresEdit

Mercury, Venus, Earth, and Mars can all appear from Ceres to cross the Sun, or transit it. The most common transits are from Mercury, which usually does so every few years, last in 2006 and next in 2010. The similar gaps are from 1953 to 2051 for Venus, 1814 to 2081 for Earth, and for Mars from 767 to 2684. [47]

Origin and evolutionEdit

The observations imply that Ceres is a surviving protoplanet (planetary embryo), which formed 4.57 billion years ago in the asteroid belt.[48] While the majority of inner solar system protoplanets (including all lunar- to Mars-sized bodies) either merged with other protoplanets to form terrestrial planets or were ejected from the Solar System by Jupiter,[48] Ceres survived relatively intact.[36] (Another possible smaller protoplanet, Vesta, suffered a catastrophic impact after solidifying.[32]) However, there is a chance that Ceres formed in the Kuiper Belt and was later captured by the asteroid belt.[49]

Further evolution of Ceres was relatively simple. Heated by the energy of accretion and by decay of various radionuclides including, possibly, short-lived elements like 26Al, Ceres differentiated into a rocky core and icy mantle soon after its formation.[4][36] This event caused resurfacing by water volcanism and tectonics, erasing older geological features.[36] However, due to its small size, Ceres cooled down quickly, and resurfacing processes stopped.[36][50] The ice on the surface gradually sublimated, leaving behind various hydrated minerals like clays and carbonates.[5] Now Ceres is a geologically dead body, whose surface is being sculptured only by impacts.[4]

The presence of significant amounts of water ice in its composition[6] raises the possibility that Ceres has or had a layer of liquid water in its interior.[36][50] This hypothetical layer is often called an ocean.[5] The water layer is (or was) probably located between the rocky core and ice mantle like that of Europa.[36] The existence of an ocean is more likely if ammonia or other antifreeze compounds are dissolved in the water.[36] The possible existence of liquid water inside Ceres makes it a target in the search for extraterrestrial life.[3]

ObservationsEdit

When Ceres has an opposition near the perihelion, it can reach a visual magnitude of +6.7.[7] This is generally regarded as being just barely too dim to be seen with the naked eye, but under exceptional viewing conditions a very sharp-sighted person may be able to see this dwarf planet. The only other asteroids that can reach a similarly bright magnitude are 4 Vesta, and, during rare oppositions near perihelion, 2 Pallas and 7 Iris.[51] At a conjunction Ceres has a magnitude of around +9.3, which corresponds to the faintest objects visible with 10×50 binoculars. It can thus be seen with binoculars whenever it is above the horizon of a fully dark sky.

Some notable observational milestones for Ceres include:

ExplorationEdit

File:Dawn Flight Configuration 2.jpg

To date, no space probe has visited Ceres. However, NASA launched the Dawn Mission on 27 September 2007, which will explore the asteroid 4 Vesta in 2011 before arriving at Ceres in 2015.[8]

The mission profile calls for the Dawn Spacecraft to enter orbit around Ceres at an altitude of 5,900 km. The spacecraft will reduce the orbital distance to 1,300 km after five months of study, and then down to 700 km after another five months.[54] The spacecraft instrumentation includes a framing camera, a visual and infrared spectrometer, and a gamma-ray and neutron detector. These will be used to examine the dwarf planet's shape and elemental composition.[8]

Radio signals from spacecraft in orbit around and on the surface of Mars have been used to estimate the mass of Ceres from its perturbations on the motion of Mars.[29]

See alsoEdit

ReferencesEdit

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Hoskin, Michael (1992-06-26). "Bodes' Law and the Discovery of Ceres". Observatorio Astronomico di Palermo "Giuseppe S. Vaiana". Retrieved on 2007-07-05.
  2. Pitjeva, E. V.; Precise determination of the motion of planets and some astronomical constants from modern observations, in Kurtz, D. W. (Ed.), Proceedings of IAU Colloquium No. 196: Transits of Venus: New Views of the Solar System and Galaxy, 2004
  3. 3.0 3.1 3.2 3.3 Moomaw, Bruce (2007-07-02). "Ceres As An Abode Of Life". spaceblooger.com. Retrieved on 2007-11-06.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Li, Jian-Yang; McFadden, Lucy A.; Parker, Joel Wm. (2006). "Photometric analysis of 1 Ceres and surface mapping from HST observations" (PDF). Icarus 182: 143–160. doi:10.1016/j.icarus.2005.12.012, http://www.astro.umd.edu/~jyli/publications/2006.Icar.182.143.pdf. Retrieved on 8 December 2007. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 Rivkin, A. S.; Volquardsen, E. L.; Clark, B. E. (2006). "The surface composition of Ceres:Discovery of carbonates and iron-rich clays" (PDF). Icarus 185: 563–567. doi:10.1016/j.icarus.2006.08.022, http://irtfweb.ifa.hawaii.edu/~elv/icarus185.563.pdf. Retrieved on 8 December 2007. 
  6. 6.0 6.1 6.2 6.3 6.4 6.5 Thomas, P. C.; Parker, J. Wm.; McFadden, L. A.; et al. (2005). "Differentiation of the asteroid Ceres as revealed by its shape". Nature 437: 224–226. doi:10.1038/nature03938, http://adsabs.harvard.edu/abs/2005Natur.437..224T. Retrieved on 9 December 2007. 
  7. 7.0 7.1 Menzel, Donald H.; and Pasachoff, Jay M. (1983). A Field Guide to the Stars and Planets (2nd edition ed.). Boston, MA: Houghton Mifflin. p. 391. ISBN 0395348358. 
  8. 8.0 8.1 8.2 Russel, C. T.; Capaccioni, F.; Coradini, A.; et al. (2006). "Dawn Discovery mission to Vesta and Ceres: Present status". Advances in Space Research 38: 2043–2048. doi:10.1016/j.asr.2004.12.041, http://adsabs.harvard.edu/abs/2006AdSpR..38.2043R. 
  9. 9.0 9.1 9.2 9.3 Hogg, Helen Sawyer (1948). "The Titius-Bode Law and the Discovery of Ceres". Journal of the Royal Astronomical Society of Canada 242: 241–246, http://adsabs.harvard.edu/abs/1948JRASC..42..241S. 
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 Forbes, Eric G. (1971). "Gauss and the Discovery of Ceres". Journal for the History of Astronomy 2: 195–199, http://adsabs.harvard.edu/abs/1971JHA.....2..195F. 
  11. Hilton, James L.. "Asteroid Masses and Densities" (PDF). U.S. Naval Observatory. Retrieved on 2008-06-23.
  12. Hughes, D. W. (1994). "The Historical Unravelling of the Diameters of the First Four Asteroids". R.A.S. Quarterly Journal 35 (3): 331, http://adsabs.harvard.edu/full/1994QJRAS..35..331H. (Page 335)
  13. Foderà Serio, G.; Manara, A.; Sicoli, P. (2002). "Giuseppe Piazzi and the Discovery of Ceres" (PDF). in W. F. Bottke Jr., A. Cellino, P. Paolicchi, and R. P. Binzel. Asteroids III. Tucson, Arizona: University of Arizona Press. pp. 17–24, http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3027.pdf. Retrieved on 25 June 2009. 
  14. Simpson, D. P. (1979). Cassell's Latin Dictionary (5 ed.). London: Cassell Ltd.. p. 883. ISBN 0-304-52257-0. 
  15. Gould, B. A. (1852). "On the symbolic notation of the asteroids". Astronomical Journal 2 (34): 80. doi:10.1086/100212, http://adsabs.harvard.edu/abs/1852AJ......2...80G. Retrieved on 5 July 2007. 
  16. Staff. "Cerium: historical information". Adaptive Optics. Retrieved on 2007-04-27.
  17. "Amalgamator Features 2003: 200 Years Ago" (October 30, 2003). Retrieved on 2006-08-21.
  18. 18.0 18.1 18.2 Hilton, James L. (September 17, 2001). "When Did the Asteroids Become Minor Planets?". Retrieved on 2006-08-16.
  19. Herschel, William (May 6, 1802). "Observations on the two lately discovered celestial Bodies.".
  20. Battersby, Stephen (August 16, 2006). "Planet debate: Proposed new definitions". New Scientist. Retrieved on 2007-04-27.
  21. Connor, Steve (August 16, 2006). "Solar system to welcome three new planets", NZ Herald. Retrieved on 27 April 2007. 
  22. Gingerich, Owen; et al. (August 16, 2006). "The IAU draft definition of "Planet" and "Plutons"". IAU. Retrieved on 2007-04-27.
  23. Staff Writers (August 16, 2006). "The IAU Draft Definition Of Planets And Plutons". SpaceDaily. Retrieved on 2007-04-27.
  24. "Question and answers 2". IAU. Retrieved on 2008-01-31. — Q: What is Ceres? "Ceres is (or now we can say it was)" - but note it then talks about "other asteroids" crossing Ceres' path.
  25. Spahr, T. B. (2006-09-07). "MPEC 2006-R19 : EDITORIAL NOTICE". Minor Planet Center. Retrieved on 2008-01-31. "the numbering of "dwarf planets" does not preclude their having dual designations in possible separate catalogues of such bodies."
  26. Stansberry, J.; Grundy, W.; Brown, M.; et al. (5 November 2007). Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope, http://arxiv.org/abs/astro-ph/0702538v1. Retrieved on 8 December 2007. 
  27. 27.0 27.1 Kovacevic, A.; Kuzmanoski, M. (2007). "A New Determination of the Mass of (1) Ceres". Earth, Moon, and Planets 100: 117–123. doi:10.1007/s11038-006-9124-4, http://adsabs.harvard.edu/abs/2007EM&P..100..117K. Retrieved on 8 December 2007. 
  28. 28.0 28.1 28.2 28.3 28.4 28.5 Carry, Benoit; et al. (November 2007). "Near-Infrared Mapping and Physical Properties of the Dwarf-Planet Ceres" (PDF). Astronomy & Astrophysics 478: 235–244. doi:10.1051/0004-6361:20078166, http://www2.keck.hawaii.edu/inst/people/conrad/nsfGrantRef/2007-arXiv-Benoit.Carry.pdf. 
  29. 29.0 29.1 Pitjeva, E. V. (2005). "High-Precision Ephemerides of Planets — EPM and Determination of Some Astronomical Constants" (PDF). Solar System Research 39 (3): 176. doi:10.1007/s11208-005-0033-2, http://iau-comm4.jpl.nasa.gov/EPM2004.pdf. Retrieved on 9 December 2007. 
  30. Carry, B.; Kaasalainen, M.; Dumas, C.; et al. (2007). "Asteroid 2 Pallas Physical Properties from Near-Infrared High-Angular Resolution Imagery" (PDF). ESO Planetary Group: Journal Club. Retrieved on 2007-11-05.
  31. Kaasalainen, M.; Torppa, J.; Piironen, J. (2002). "Models of Twenty Asteroids from Photometric Data" (PDF). Icarus 159: 369–395. doi:10.1006/icar.2002.6907, http://www.rni.helsinki.fi/~mjk/IcarPIII.pdf. Retrieved on 25 June 2009. 
  32. 32.0 32.1 Thomas, Peter C.; Binzel, Richard P.; Gaffey, Michael J.; et al. (1997). "Impact Excavation on Asteroid 4 Vesta: Hubble Space Telescope Results". Science 277: 1492–1495. doi:10.1126/science.277.5331.1492, http://www.sciencemag.org/cgi/content/abstract/277/5331/1492. Retrieved on 8 December 2007. 
  33. Barucci, M (2002). "10 Hygiea: ISO Infrared Observations". Icarus 156: 202. doi:10.1006/icar.2001.6775. 
  34. 0.72-0.77 anhydrous rock by mass, per William B. McKinnon, 2008, "On The Possibility Of Large KBOs Being Injected Into The Outer Asteroid Belt". American Astronomical Society, DPS meeting #40, #38.03[1]
  35. Carey, Bjorn (7 September 2005). "Largest Asteroid Might Contain More Fresh Water than Earth", SPACE.com. Retrieved on 16 August 2006. 
  36. 36.0 36.1 36.2 36.3 36.4 36.5 36.6 36.7 McCord, Thomas B. (2005). "Ceres: Evolution and current state". Journal of Geophysical Research 110: E05009. doi:10.1029/2004JE002244, http://adsabs.harvard.edu/abs/2005JGRE..11005009M. 
  37. 37.0 37.1 37.2 Parker, J. W.; Stern, Alan S.; Thomas Peter C.; et al. (2002). "Analysis of the first disk-resolved images of Ceres from ultraviolet observations with the Hubble Space Telescope". The Astrophysiscal Journal 123: 549–557. doi:10.1086/338093, http://adsabs.harvard.edu/abs/2002AJ....123..549P. 
  38. Cite error: Invalid <ref> tag; no text was provided for refs named Saint-Pe1993
  39. 39.0 39.1 39.2 Staff (October 11, 2006). "Keck Adaptive Optics Images the Dwarf Planet Ceres". Adaptive Optics. Retrieved on 2007-04-27.
  40. 40.0 40.1 "Largest Asteroid May Be 'Mini Planet' with Water Ice", HubbleSite (September 7, 2005). Retrieved on 16 August 2006. 
  41. 41.0 41.1 A’Hearn, Michael F.; Feldman, Paul D. (1992). "Water vaporization on Ceres". Icarus 98: 54–60. doi:10.1016/0019-1035(92)90206-M, http://adsabs.harvard.edu/abs/1992Icar...98...54A. Retrieved on 8 December 2007. 
  42. "Hubble Directly Observes Planet Orbiting Fomalhaut". Hubblesite (November 13, 2008). Retrieved on 2009-07-02.
  43. Cite error: Invalid <ref> tag; no text was provided for refs named jpl_sbdb
  44. 44.0 44.1 Cellino, A.; et al.; "Spectroscopic Properties of Asteroid Families", in Asteroids III, pp. 633-643, University of Arizona Press (2002). (Table on page 636, in particular).
  45. Kelley, M. S.; Gaffey, M. J. (1996). "A Genetic Study of the Ceres (Williams #67) Asteroid Family". Bulletin of the American Astronomical Society 28: 1097, http://adsabs.harvard.edu/abs/1996BAAS...28R1097K. Retrieved on 27 April 2007. 
  46. Williams, David R. (2004). Asteroid Fact Sheet, http://nssdc.gsfc.nasa.gov/planetary/factsheet/asteroidfact.html. 
  47. "Solex". Retrieved on 2009-03-03 numbers generated by Solex.
  48. 48.0 48.1 Petit, Jean-Marc; Morbidelli, Alessandro (2001). "The Primordial Excitation and Clearing of the Asteroid Belt" (PDF). Icarus 153: 338–347. doi:10.1006/icar.2001.6702, http://www.gps.caltech.edu/classes/ge133/reading/asteroids.pdf. Retrieved on 25 June 2009. 
  49. About a 10 % chance of the asteroid belt acquiring a Ceres-mass KBO. William B. McKinnon, 2008, "On The Possibility Of Large KBOs Being Injected Into The Outer Asteroid Belt". American Astronomical Society, DPS meeting #40, #38.03[2]
  50. 50.0 50.1 Castillo-Rogez, J. C.; McCord, T. B.; and Davis, A. G. (2007). "Ceres: evolution and present state" (PDF). Lunar and Planetary Science XXXVIII: 2006–2007, http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2006.pdf. Retrieved on 25 June 2009. 
  51. Martinez, Patrick, The Observer's Guide to Astronomy, page 298. Published 1994 by Cambridge University Press
  52. Millis, L. R.; Wasserman, L. H.; Franz, O. Z.; et al. (1987). "The size, shape, density, and albedo of Ceres from its occultation of BD+8 deg 471". Icarus 72: 507–518. doi:10.1016/0019-1035(87)90048-0, http://adsabs.harvard.edu/abs/1987Icar...72..507M. 
  53. "Observations reveal curiosities on the surface of asteroid Ceres". Retrieved on 2006-08-16.
  54. Rayman, Marc (13 July 2006). "Dawn: mission description". UCLA — IGPP Space Physics Center. Archived from the original on 2012-06-04. Retrieved on 2007-04-27.

EphemeridesEdit

External linksEdit

Template:Ceres

af:Ceres (dwergplaneet) als:(1) Ceres ar:سيريس (كوكب قزم) ast:1 Ceres az:Serera (cırtdan planet) bn:সেরেস zh-min-nan:Ceres (é-he̍k-chheⁿ) be-x-old:Цэрэра (карлікавая плянэта) br:Keres (planedenn-gorr) bg:1 Церера ca:Ceres (planeta nan) cv:Церера (астероид) cs:Ceres (trpasličí planeta) co:Cerere (astrunumia) cy:Ceres (planed gorrach) da:Ceres (dværgplanet)et:Ceres (kääbusplaneet) el:Δήμητρα (πλανήτης νάνος)eo:Cereso eu:1 Ceres fa:سرسga:Ceiréas (abhacphlainéad) gv:Keres (planaid crivassanagh) gl:Ceres (planeta anano) gu:સિરસ (વામન ગ્રહ)hi:सीरिस ग्रह hr:1 Ceres io:Ceres id:1 Ceres ia:Ceres (planeta nano) is:Seres (dvergreikistjarna) it:Cerere (astronomia) he:קרס (כוכב לכת ננסי) jv:Ceres ka:ცერერა (პლანეტა) kk:Серера (шағын ғаламшар) kw:Ceres (planet còr) la:Ceres (planetula) lv:Cerera lb:Ceres (Zwergplanéit) lt:Cerera (nykštukinė planeta) li:Ceres (dwergplaneet) hu:Ceres (törpebolygó) mk:Церес ml:സീറീസ് mr:सेरेस (बटु ग्रह) ms:Ceres (planet kerdil) mn:Церера my:စီးရပ်စ် (ဂြိုလ်သိမ်ဂြိုလ်မွှား) nah:Ceres nl:Ceres (dwergplaneet)no:Ceres (dvergplanet) nn:1 Ceres nds:Ceres (Dwargplanet) pl:1 Ceres pt:Ceres (planeta anão) ro:Ceres (planetă pitică) rm:Ceres (planet nanin) qu:Siris (tuna puriq quyllur)scn:Cèriri simple:Ceres (dwarf planet) sk:1 Ceres sl:Cerera (pritlikavi planet) sr:Церера (патуљаста планета) sh:1 Ceres fi:Ceres sv:Ceres (dvärgplanet) tl:Seres (astronomiya) te:సెరిస్ (మరుగుజ్జు గ్రహం) th:ซีรีส tg:Серера tr:Ceres (cüce gezegen) uk:Церера (карликова планета) ug:سېرېرا vi:Ceres (hành tinh lùn)

Ad blocker interference detected!


Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.