Ceres ( dwarf planet ) - wikipedia Ceres ( dwarf planet ) This is an old revision of this page, as edited by KolbertBot ( talk contribs ) at 10 : 49, 28 August 2017 ( Bot : HTTP → HTTPS ). The present address ( URL ) is a permanent link to this revision, which may differ significantly from the current revision. Revision as of 10 : 49, 28 August 2017 by KolbertBot ( talk contribs ) ( Bot : HTTP → HTTPS ) ( diff ) ← Previous revision Latest revision ( diff ) Newer revision → ( diff ) Ceres A view of Ceres in natural color, pictured by the Dawn spacecraft in May 2015. Discovery Discovered by Giuseppe Piazzi Discovery date 1 January 1801 Designations MPC designation 1 Ceres Pronunciation / ˈsɪəriːz / Named after Cerēs Alternative names A899 OF ; 1943 XB Minor planet category Dwarf planet Asteroid belt Adjectives Cererian / sɪˈrɪəriən /, rarely Cererean / sɛrɪˈriːən / Orbital characteristics Epoch 2014 - Dec - 09 ( JD 7006245700050000000 ♠ 2,457,000.5 ) Aphelion 7011445397740435110 ♠ 2.9773 AU ( 7011445410000000000 ♠ 445,410,000 km ) Perihelion 7011382626473889390 ♠ 2.5577 AU ( 7011382620000000000 ♠ 382,620,000 km ) Semi-major axis 7011414012107162250 ♠ 2.7675 AU ( 7011414010000000000 ♠ 414,010,000 km ) Eccentricity 6998758230000000000 ♠ 0.075 823 Orbital period 4.60 yr 1,681.63 d Synodic period 466.6 d 1.278 yr Average orbital speed 7004179050000000000 ♠ 17.905 km / s Mean anomaly 7000167532584102609 ♠ 95.9891 ° Inclination 6999184882727663759 ♠ 10.593 ° to ecliptic 9.20 ° to invariable plane Longitude of ascending node 7000140201077082228 ♠ 80.3293 ° Argument of perihelion 7000126574768013133 ♠ 72.5220 ° Satellites None Proper orbital elements Proper semi-major axis 7000276709620000000 ♠ 2.767 0962 AU Proper eccentricity 6999116197700000000 ♠ 0.116 1977 Proper inclination 6999168379107187070 ♠ 9.647 4122 ° Proper mean motion 78.193318 deg / yr Proper orbital period 4.60397 yr ( 1681.601 d ) Precession of perihelion 7001540702720000000 ♠ 54.070 272 arcsec / yr Precession of the ascending node 2998408299660000000 ♠ − 59.170 034 arcsec / yr Physical characteristics Dimensions ( 7002965200000000000 ♠ 965.2 × 7002961200000000000 ♠ 961.2 × 7002891200000000000 ♠ 891.2 ) ± 2.0 km Mean radius 7005473000000000000 ♠ 473 km Surface area 7012277000000000000 ♠ 2,770,000 km Volume 7017421000000000000 ♠ 421,000,000 km Mass 7020939300000000000 ♠ ( 9.393 ± 0.005 ) × 10 kg 6996150000000000000 ♠ 0.000 15 Earths 0.0128 Moons Mean density 7003216100000000000 ♠ 2.161 ± 0.009 g / cm Surface gravity 0.28 m / s 0.029 g Moment of inertia factor 6999370000000000000 ♠ 0.37 ( estimate ) Escape velocity 0.51 km / s Sidereal rotation period 7004326678400000000 ♠ 0.3781 d 7004326670120000000 ♠ 9.074 170 ± 0.000 002 h Equatorial rotation velocity 7001926100000000000 ♠ 92.61 m / s Axial tilt 4 ° North pole right ascension 291.418 ° North pole declination 66.764 ° Albedo 6998900000000000000 ♠ 0.090 ± 0.0033 ( V - band geometric ) Surface temp. min mean max Kelvin ? ≈ 168 K 235 K Spectral type C Apparent magnitude 6.64 to 9.34 Absolute magnitude ( H ) 7000336000000000000 ♠ 3.36 ± 0.02 Angular diameter 0.854 '' to 0.339 '' Ceres ( / ˈsɪəriːz / ; minor - planet designation : 1 Ceres ) is the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter. Its diameter is approximately 945 kilometers ( 587 miles ), making it the largest of the minor planets within the orbit of Neptune. The 33rd - largest known body in the Solar System, it is the only dwarf planet within the orbit of Neptune. Composed of rock and ice, Ceres is estimated to compose approximately one third of the mass of the entire asteroid belt. Ceres is the only object in the asteroid belt known to be rounded by its own gravity ( though detailed analysis was required to exclude 4 Vesta ). From Earth, the apparent magnitude of Ceres ranges from 6.7 to 9.3, and hence even at its brightest it is too dim to be seen with the naked eye except under extremely dark skies. Ceres was the first asteroid to be discovered ( by Giuseppe Piazzi at Palermo on 1 January 1801 ). It was originally considered a planet, but was reclassified as an asteroid in the 1850s after many other objects in similar orbits were discovered. Ceres appears to be differentiated into a rocky core and an icy mantle, and may have a remnant internal ocean of liquid water under the layer of ice. The surface is probably a mixture of water ice and various hydrated minerals such as carbonates and clay. In January 2014, emissions of water vapor were detected from several regions of Ceres. This was unexpected because large bodies in the asteroid belt typically do not emit vapor, a hallmark of comets. The robotic NASA spacecraft Dawn entered orbit around Ceres on 6 March 2015. Pictures with a resolution previously unattained were taken during imaging sessions starting in January 2015 as Dawn approached Ceres, showing a cratered surface. Two distinct bright spots ( or high - albedo features ) inside a crater ( different from the bright spots observed in earlier Hubble images ) were seen in a 19 February 2015 image, leading to speculation about a possible cryovolcanic origin or outgassing. On 3 March 2015, a NASA spokesperson said the spots are consistent with highly reflective materials containing ice or salts, but that cryovolcanism is unlikely. However, on 2 September 2016, NASA scientists released a paper in Science that claimed that a massive ice volcano called Ahuna Mons is the strongest evidence yet for the existence of these mysterious ice volcanoes. On 11 May 2015, NASA released a higher - resolution image showing that, instead of one or two spots, there are actually several. On 9 December 2015, NASA scientists reported that the bright spots on Ceres may be related to a type of salt, particularly a form of brine containing magnesium sulfate hexahydrite ( MgSO 6H O ) ; the spots were also found to be associated with ammonia - rich clays. In June 2016, near - infrared spectra of these bright areas were found to be consistent with a large amount of sodium carbonate ( Na 2CO 3 ), implying that recent geologic activity was probably involved in the creation of the bright spots. In October 2015, NASA released a true color portrait of Ceres made by Dawn. In February 2017, organics were reported to have been detected on Ceres in Ernutet crater ( see image ). Contents 1 History 1.1 Discovery 1.2 Name 1.3 Classification 2 Orbit 2.1 Resonances 2.2 Transits of planets from Ceres 3 Rotation and axial tilt 4 Geology 4.1 Surface 4.1. 1 Observations prior to Dawn 4.1. 2 Observations by Dawn 4.2 Internal structure 5 Atmosphere 6 Origin and evolution 7 Potential habitability 8 Observation and exploration 8.1 Observation 8.2 Exploration 9 Maps 9.1 Map of quadrangles 10 Gallery 10.1 True - color images 10.2 Animations 11 See also 12 Notes 13 References 14 External links History Discovery Piazzi 's book Della scoperta del nuovo pianeta Cerere Ferdinandea outlining the discovery of Ceres, dedicated the new `` planet '' to Ferdinand I of the Two Sicilies. Johann Elert Bode, in 1772, first suggested that an undiscovered planet could exist between the orbits of Mars and Jupiter. Kepler had already noticed the gap between Mars and Jupiter in 1596. Bode based his idea on the Titius -- Bode law which is a now - discredited hypothesis that was first proposed in 1766. Bode observed that there was a regular pattern in the semi-major axes of the orbits of known planets, and that the pattern was marred only by the large gap between Mars and Jupiter. The pattern predicted that the missing planet ought to have an orbit with a semi-major axis near 2.8 astronomical units ( AU ). William Herschel 's discovery of Uranus in 1781 near the predicted distance for the next body beyond Saturn increased faith in the law of Titius and Bode, and in 1800, a group headed by Franz Xaver von Zach, editor of the Monatliche Correspondenz, sent requests to twenty - four experienced astronomers ( whom he dubbed the `` celestial police '' ), asking that they combine their efforts and begin a methodical search for the expected planet. Although they did not discover Ceres, they later found several large asteroids. One of the astronomers selected for the search was Giuseppe Piazzi, a Catholic priest at the Academy of Palermo, Sicily. Before receiving his invitation to join the group, Piazzi discovered Ceres on 1 January 1801. He was searching for `` the 87th ( star ) of the Catalogue of the Zodiacal stars of Mr la Caille '', but found that `` it was preceded by another ''. Instead of a star, Piazzi had found a moving star - like object, which he first thought was a comet. Piazzi observed Ceres a total of 24 times, the final time on 11 February 1801, when illness interrupted his observations. He announced his discovery on 24 January 1801 in letters to only two fellow astronomers, his compatriot Barnaba Oriani of Milan and Bode of Berlin. 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 ''. In April, Piazzi sent his complete observations to Oriani, Bode, and Jérôme Lalande in Paris. The information was published in the September 1801 issue of the Monatliche Correspondenz. By this time, the apparent position of Ceres had changed ( mostly due to Earth 's orbital motion ), and was too close to the Sun 's glare for other astronomers to confirm Piazzi 's observations. Toward the end of the year, Ceres should have been visible again, but 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. In only a few weeks, he predicted the path of Ceres 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. The early observers were only able to calculate the size of Ceres to within an order of magnitude. Herschel underestimated its diameter as 260 km in 1802, whereas in 1811 Johann Hieronymus Schröter overestimated it as 2,613 km. Name Piazzi originally suggested the name Cerere Ferdinandea for his discovery, after the goddess Ceres ( Roman goddess of agriculture, Cerere in Italian, who was believed to have originated in Sicily and whose oldest temple was there ) and King Ferdinand of Sicily. `` Ferdinandea '', however, was not acceptable to other nations and was dropped. Ceres was called Hera for a short time in Germany. In Greece, it is called Demeter ( Δήμητρα ), after the Greek equivalent of the Roman Cerēs ; in English, that name is used for the asteroid 1108 Demeter. The regular adjectival forms of the name are Cererian and Cererean, derived from the Latin genitive Cereris, but Ceresian is occasionally seen for the goddess ( as in the sickle - shaped Ceresian Lake ), as is the shorter form Cerean. The old astronomical symbol of Ceres is a sickle, ⟨ ⚳ ⟩ ( ), similar to Venus ' symbol ⟨ ♀ ⟩ but with a break in the circle. It has a variant ⟨ ⟩, reversed under the influence of the initial letter ' C ' of ' Ceres '. These were later replaced with the generic asteroid symbol of a numbered disk, ⟨ 1 ⟩. Cerium, a rare - earth element discovered in 1803, was named after Ceres. In the same year another element was also initially named after Ceres, but when cerium was named, its discoverer changed the name to palladium, after the second asteroid, 2 Pallas. Classification The categorization 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. 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 half a century. Sizes of the first ten main - belt objects discovered profiled against the Moon. Ceres is far left ( 1 ). As other objects were discovered in the neighborhood of Ceres, it was realized that Ceres represented the first of a new class of objects. In 1802, with the discovery of 2 Pallas, William Herschel coined the term asteroid ( `` star - like '' ) for these bodies, writing that `` they resemble small stars so much as hardly to be distinguished from them, even by very good telescopes ''. As the first such body to be discovered, Ceres was given the designation 1 Ceres under the modern system of minor - planet designations. By the 1860s, the existence of a fundamental difference between asteroids such as Ceres and the major planets was widely accepted, though a precise definition of `` planet '' was never formulated. Ceres ( bottom left ), the Moon and Earth, shown to scale Size comparison of Vesta, Ceres and Eros The 2006 debate surrounding Pluto and what constitutes a planet led to Ceres being considered for reclassification as a planet. 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 ''. Had this resolution been adopted, it would have made Ceres the fifth planet in order from the Sun. This never happened, however, and on 24 August 2006 a modified definition was adopted, carrying the additional requirement that a planet must have `` cleared the neighborhood around its orbit ''. By this definition, Ceres is not a planet because it does not dominate its orbit, sharing it as it does with the thousands of other asteroids in the asteroid belt and constituting only about a third of the mass of the belt. Bodies that met the first proposed definition but not the second, such as Ceres, were instead classified as dwarf planets. Ceres is the largest object in the asteroid belt. It is sometimes assumed that Ceres has been reclassified as a dwarf planet, and that it is therefore no longer considered an asteroid. For example, a news update at Space.com spoke of `` Pallas, the largest asteroid, and Ceres, the dwarf planet formerly classified as an asteroid '', whereas an IAU question - and - answer posting states, `` Ceres is ( or now we can say it was ) the largest asteroid '', though it then speaks of `` other asteroids '' crossing Ceres ' path and otherwise implies that Ceres is still considered an asteroid. The Minor Planet Center notes that such bodies may have dual designations. The 2006 IAU decision that classified Ceres as a dwarf planet never addressed whether it is or is not an asteroid. Indeed, the IAU has never defined the word ' asteroid ' at all, having preferred the term ' minor planet ' until 2006, and preferring the terms ' small Solar System body ' and ' dwarf planet ' after 2006. Lang ( 2011 ) comments `` the ( IAU has ) added a new designation to Ceres, classifying it as a dwarf planet... By ( its ) definition, Eris, Haumea, Makemake and Pluto, as well as the largest asteroid, 1 Ceres, are all dwarf planets '', and describes it elsewhere as `` the dwarf planet -- asteroid 1 Ceres ''. NASA continues to refer to Ceres as an asteroid, as do various academic textbooks. Orbit Proper ( long - term mean ) orbital elements compared to osculating ( instant ) orbital elements for Ceres : Element type a ( in AU ) i Period ( in days ) Proper 2.7671 0.116198 9.647435 1,681.60 Osculating ( Epoch 23 July 2010 ) 2.7653 0.079138 10.586821 1,679.66 Difference 0.0018 0.03706 0.939386 1.94 Orbit of Ceres Ceres follows an orbit between Mars and Jupiter, within the 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 ). The diagram illustrates the orbits of Ceres ( blue ) and several planets ( white and gray ). The segments of orbits below the ecliptic are plotted in darker colors, 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. In this diagram ( but not in general ), 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 side view showing the inclination of the orbit of Ceres compared to the orbits of Mars and Jupiter. Ceres was once thought to be a member of an asteroid family. The asteroids of this family share similar proper orbital elements, which may indicate a common origin through an asteroid collision some time in the past. Ceres was later found to have spectral properties different from other members of the family, which is now called the Gefion family after the next - lowest - numbered family member, 1272 Gefion. Ceres appears to be merely an interloper in the Gefion family, coincidentally having similar orbital elements but not a common origin. Resonances Ceres is in a near - 1 : 1 mean - motion orbital resonance with Pallas ( their proper orbital periods differ by 0.2 % ). However, a true resonance between the two would be unlikely ; due to their small masses relative to their large separations, such relationships among asteroids are very rare. Nevertheless, Ceres is able to capture other asteroids into temporary 1 : 1 resonant orbital relationships ( making them temporary trojans ) for periods up to 2 million years or more ; fifty such objects have been identified. Transits of planets from Ceres Mercury, Venus, Earth, and Mars can all appear to cross the Sun, or transit it, from a vantage point on Ceres. The most common transits are those of Mercury, which usually happen every few years, most recently in 2006 and 2010. The most recent transit of Venus was in 1953, and the next will be in 2051 ; the corresponding dates are 1814 and 2081 for transits of Earth, and 767 and 2684 for transits of Mars. Rotation and axial tilt The rotation period of Ceres ( the Cererian day ) is 9 hours and 4 minutes. It has an axial tilt of 4 °. This is small enough for Ceres 's polar regions to contain permanently shadowed craters that are expected to act as cold traps and accumulate water ice over time, similar to the situation on the Moon and Mercury. About 0.14 % of water molecules released from the surface are expected to end up in the traps, hopping an average of 3 times before escaping or being trapped. Geology Main article : Geology of Ceres Ceres has a mass of 7020939000000000000 ♠ 9.39 × 10 kg as determined from the Dawn spacecraft. With this mass Ceres composes approximately a third of the estimated total 3.0 ± 0.2 × 10 kg mass of the asteroid belt, which is in turn approximately 4 % of the mass of the Moon. Ceres is massive enough to give it a nearly spherical, equilibrium shape. Among Solar System bodies, Ceres is intermediate in size between the smaller Vesta and the larger Tethys. Its surface area is approximately the same as the land area of India or Argentina. Surface Main article : List of geological features on Ceres The surface composition of Ceres is broadly similar to that of C - type asteroids. Some differences do exist. The ubiquitous features in Ceres ' IR spectrum are those of hydrated materials, which indicate the presence of significant amounts of water in its interior. Other possible surface constituents include iron - rich clay minerals ( cronstedtite ) and carbonate minerals ( dolomite and siderite ), which are common minerals in carbonaceous chondrite meteorites. The spectral features of carbonates and clay minerals are usually absent in the spectra of other C - type asteroids. Sometimes Ceres is classified as a G - type asteroid. Ceres ' surface is relatively warm. The maximum temperature with the Sun overhead was estimated from measurements to be 235 K ( approximately − 38 ° C, − 36 ° F ) on 5 May 1991. Ice is unstable at this temperature. Material left behind by the sublimation of surface ice could explain the dark surface of Ceres compared to the icy moons of the outer Solar System. Studies by the Hubble Space Telescope reveal that graphite, sulfur, and sulfur dioxide are present on Ceres 's surface. The former is evidently the result of space weathering on Ceres 's older surfaces ; the latter two are volatile under Cerean conditions and would be expected to either escape quickly or settle in cold traps, and are evidently associated with areas with recent geological activity. Observations prior to Dawn HST images taken over a span of 2 hours and 20 minutes in 2004 Prior to the Dawn mission, only a few surface features had been unambiguously detected on Ceres. High - resolution ultraviolet Hubble Space Telescope images taken in 1995 showed a dark spot on its surface, which was nicknamed `` Piazzi '' in honor of the discoverer of Ceres. 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 Ceres ' rotation. Two dark features had circular shapes and were presumed to be craters ; one of them was observed to have a bright central region, whereas another was identified as the `` Piazzi '' feature. Visible - light Hubble Space Telescope images of a full rotation taken in 2003 and 2004 showed eleven recognizable surface features, the natures of which were then undetermined. One of these features corresponds to the `` Piazzi '' feature observed earlier. These last observations indicated that the north pole of Ceres pointed in the direction of right ascension 19 h 24 min ( 291 ° ), declination + 59 °, in the constellation Draco, resulting in an axial tilt of approximately 3 °. Dawn later determined that the north polar axis actually points at right ascension 19 h 25 m 40.3 s ( 291.418 ° ), declination + 66 ° 45 ' 50 '' ( about 1.5 degrees from Delta Draconis ), which means an axial tilt of 4 °. Observations by Dawn Play media Permanently shadowed regions capable of accumulating surface ice were identified in the northern hemisphere of Ceres using Dawn. Dawn revealed that Ceres has a heavily cratered surface ; nevertheless, Ceres does not have as many large craters as expected, likely due to past geological processes. An unexpectedly large number of Cererian craters have central pits, perhaps due to cryovolcanic processes, and many have central peaks. Ceres has one prominent mountain, Ahuna Mons ; this peak appears to be a cryovolcano and has few craters, suggesting a maximum age of no more than a few hundred million years. A later computer simulation has suggested that there were originally other cryovolcanoes on Ceres that are now unrecognisable due to viscous relaxation. Several bright spots have been observed by Dawn, the brightest spot ( `` Spot 5 '' ) located in the middle of an 80 - kilometer ( 50 mi ) crater called Occator. From images taken of Ceres on 4 May 2015, the secondary bright spot was revealed to actually be a group of scattered bright areas, possibly as many as ten. These bright features have an albedo of approximately 40 % that are caused by a substance on the surface, possibly ice or salts, reflecting sunlight. A haze periodically appears above Spot 5, the best known bright spot, supporting the hypothesis that some sort of outgassing or sublimating ice formed the bright spots. In March 2016, Dawn found definitive evidence of water molecules on the surface of Ceres at Oxo crater. JPL states : `` This water could be bound up in minerals or, alternatively, it could take the form of ice. '' On 9 December 2015, NASA scientists reported that the bright spots on Ceres may be related to a type of salt, particularly a form of brine containing magnesium sulfate hexahydrite ( MgSO 6H O ) ; the spots were also found to be associated with ammonia - rich clays. Another team thinks the salts are sodium carbonate. Map of bright spots on Ceres ( released 10 December 2015 ). Bright spots on Ceres in visible and infrared : `` Spot 1 '' ( top row ) ( `` cooler '' than surroundings ) ; `` Spot 5 '' ( bottom ) ( `` similar in temperature '' as surroundings ) ( April 2015 ) `` Bright Spot 5 '' in the crater Occator. Imaged by Dawn from 385 km ( 239 mi ) ( LAMO ) Ahuna Mons is an estimated 5 km ( 3 mi ) high on its steepest side. Imaged by Dawn from 385 km ( 239 mi ) in December 2015. Internal structure Diagram showing a possible internal structure of Ceres Ceres ' oblateness is consistent with a differentiated body, a rocky core overlain with an icy mantle. This 100 - kilometer - thick mantle ( 23 % -- 28 % of Ceres by mass ; 50 % by volume ) contains up to 200 million cubic kilometers of water, which would be more than the amount of fresh water on Earth. This result is supported by the observations made by the Keck telescope in 2002 and by evolutionary modeling. 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. It has been suggested that a remnant layer of liquid water may have survived to the present under a layer of ice. Shape and gravity field measurements by Dawn confirm Ceres is a body in hydrostatic equilibrium with partial differentiation and isostatic compensation, with a mean moment of inertia of 0.37 ( which is similar to that of Callisto at ~ 0.36 ). The densities of the core and outer layer are estimated to be 2.46 -- 2.90 and 1.68 -- 1.95 g / cm, with the latter being about 70 -- 190 km thick. Only partial dehydration of the core is expected. The high density of the outer layer ( relative to water ice ) reflects its enrichment in silicates and salts. Ceres is the smallest object confirmed to be in hydrostatic equilibrium, being 600 km smaller and less than half the mass of Saturn 's moon Rhea, the next smallest such object. Modeling has suggested Ceres could have a small metallic core from partial differentiation of its rocky fraction. Atmosphere There are indications that Ceres has a tenuous water vapor atmosphere outgassing from water ice on the surface. Surface water ice is unstable at distances less than 5 AU from the Sun, so it is expected to sublime if it is exposed directly to solar radiation. Water ice can migrate from the deep layers of Ceres to the surface, but escapes in a very short time. As a result, it is difficult to detect water vaporization. Water escaping from polar regions of Ceres was possibly observed in the early 1990s but this has not been unambiguously demonstrated. It may be possible to detect escaping water from the surroundings of a fresh impact crater or from cracks in the subsurface layers of Ceres. Ultraviolet observations by the IUE spacecraft detected statistically significant amounts of hydroxide ions near Ceres ' north pole, which is a product of water vapor dissociation by ultraviolet solar radiation. In early 2014, using data from the Herschel Space Observatory, it was discovered that there are several localized ( not more than 60 km in diameter ) mid-latitude sources of water vapor on Ceres, which each give off approximately 7026100000000000000 ♠ 10 molecules ( or 3 kg ) of water per second. Two potential source regions, designated Piazzi ( 123 ° E, 21 ° N ) and Region A ( 231 ° E, 23 ° N ), have been visualized in the near infrared as dark areas ( Region A also has a bright center ) by the W.M. Keck Observatory. Possible mechanisms for the vapor release are sublimation from approximately 0.6 km of exposed surface ice, or cryovolcanic eruptions resulting from radiogenic internal heat or from pressurization of a subsurface ocean due to growth of an overlying layer of ice. Surface sublimation would be expected to be lower when Ceres is farther from the Sun in its orbit, whereas internally powered emissions should not be affected by its orbital position. The limited data available was more consistent with cometary - style sublimation ; however, subsequent evidence from Dawn strongly suggests ongoing geologic activity could be at least partially responsible. Studies using Dawn 's gamma ray and neutron detector ( GRaND ) reveal that Ceres is accelerating electrons from the solar wind regularly ; although there are several possibilities as to what is causing this, the most accepted is that these electrons are being accelerated by collisions between the solar wind and a tenuous water vapor exosphere. In 2017, Dawn confirmed that Ceres has a transient atmosphere that appears to be linked to solar activity. Ice on Ceres can sublimate when energetic particles from the Sun hit exposed ice within craters. Origin and evolution Ceres is possibly a surviving protoplanet ( planetary embryo ), which formed 4.57 billion years ago in the asteroid belt. Although 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, Ceres is thought to have survived relatively intact. An alternative theory proposes that Ceres formed in the Kuiper belt and later migrated to the asteroid belt. The discovery of ammonia salts in Occator crater supports an origin in the outer Solar System. Another possible protoplanet, Vesta, is less than half the size of Ceres ; it suffered a major impact after solidifying, losing ~ 1 % of its mass. The geological evolution of Ceres was dependent on the heat sources available during and after its formation : friction from planetesimal accretion, and decay of various radionuclides ( possibly including short - lived extinct radionuclides such as aluminium - 26 ). These are thought to have been sufficient to allow Ceres to differentiate into a rocky core and icy mantle soon after its formation. This process may have caused resurfacing by water volcanism and tectonics, erasing older geological features. Ceres 's relatively warm surface temperature implies that any of the resulting ice on its surface would have gradually sublimated, leaving behind various hydrated minerals like clay minerals and carbonates. Today, Ceres has become considerably less geologically active, with a surface sculpted chiefly by impacts ; nevertheless, evidence from Dawn reveals that internal processes have continued to sculpt Ceres 's surface to a significant extent, in stark contrast to Vesta and of previous expectations that Ceres would have become geologically dead early in its history due to its small size. The presence of significant amounts of water ice in its composition and evidence of recent geological resurfacing, raises the possibility that Ceres has a layer of liquid water in its interior. This hypothetical layer is often called an ocean. If such a layer of liquid water exists, it is hypothesized to be located between the rocky core and ice mantle like that of the theorized ocean on Europa. The existence of an ocean is more likely if solutes ( i.e. salts ), ammonia, sulfuric acid or other antifreeze compounds are dissolved in the water. Potential habitability Although not as actively discussed as a potential home for microbial extraterrestrial life as Mars, Titan, Europa or Enceladus, there is evidence that Ceres ' icy mantle was once a watery subterranean ocean, and that has led to speculations that life could have existed there, and that hypothesized ejecta bearing microorganisms could have come from Ceres to Earth. Observation and Exploration Observation Polarimetric map of Ceres When Ceres has an opposition near the perihelion, it can reach a visual magnitude of + 6.7. This is generally regarded as too dim to be seen with the naked eye, but under exceptional viewing conditions a very sharp - sighted person may be able to see it. 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. 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 observations and milestones for Ceres include : 1984 November 13 : An occultation of a star by Ceres observed in Mexico, Florida and across the Caribbean. 1995 June 25 : Ultraviolet Hubble Space Telescope images with 50 - kilometer resolution. 2002 : Infrared images with 30 - km resolution taken with the Keck telescope using adaptive optics. 2003 and 2004 : Visible light images with 30 - km resolution ( the best prior to the Dawn mission ) taken using Hubble. 2012 December 22 : Ceres occulted the star TYC 1865 - 00446 - 1 over parts of Japan, Russia, and China. Ceres ' brightness was magnitude 6.9 and the star, 12.2. 2014 : Ceres was found to have an atmosphere with water vapor, confirmed by the Herschel space telescope. 2015 : The NASA Dawn spacecraft approached and orbited Ceres, sending detailed images and scientific data back to Earth. Exploration Artist 's conception of Dawn, travelling from Vesta to Ceres In 1981, a proposal for an asteroid mission was submitted to the European Space Agency ( ESA ). Named the Asteroidal Gravity Optical and Radar Analysis ( AGORA ), this spacecraft was to launch some time in 1990 -- 1994 and perform two flybys of large asteroids. The preferred target for this mission was Vesta. AGORA would reach the asteroid belt either by a gravitational slingshot trajectory past Mars or by means of a small ion engine. However, the proposal was refused by ESA. A joint NASA -- ESA asteroid mission was then drawn up for a Multiple Asteroid Orbiter with Solar Electric Propulsion ( MAOSEP ), with one of the mission profiles including an orbit of Vesta. NASA indicated they were not interested in an asteroid mission. Instead, ESA set up a technological study of a spacecraft with an ion drive. Other missions to the asteroid belt were proposed in the 1980s by France, Germany, Italy, and the United States, but none were approved. Exploration of Ceres by fly - by and impacting penetrator was the second main target of the second plan of the multiaimed Soviet Vesta mission, developed in cooperation with European countries for realisation in 1991 -- 1994 but canceled due to the Soviet Union disbanding. First asteroid image ( Ceres and Vesta ) from Mars -- viewed by Curiosity ( 20 April 2014 ) In the early 1990s, NASA initiated the Discovery Program, which was intended to be a series of low - cost scientific missions. In 1996, the program 's study team recommended as a high priority a mission to explore the asteroid belt using a spacecraft with an ion engine. Funding for this program remained problematic for several years, but by 2004 the Dawn vehicle had passed its critical design review. It was launched on 27 September 2007, as the space mission to make the first visits to both Vesta and Ceres. On 3 May 2011, Dawn acquired its first targeting image 1.2 million kilometers from Vesta. After orbiting Vesta for 13 months, Dawn used its ion engine to depart for Ceres, with gravitational capture occurring on 6 March 2015 at a separation of 61,000 km, four months prior to the New Horizons flyby of Pluto. Dawn 's mission profile calls for it to study Ceres from a series of circular polar orbits at successively lower altitudes. It entered its first observational orbit ( `` RC3 '' ) around Ceres at an altitude of 13,500 km on 23 April 2015, staying for only approximately one orbit ( fifteen days ). The spacecraft will subsequently reduce its orbital distance to 4,400 km for its second observational orbit ( `` survey '' ) for three weeks, then down to 1,470 km ( `` HAMO ; '' high altitude mapping orbit ) for two months and then down to its final orbit at 375 km ( `` LAMO ; '' low altitude mapping orbit ) for at least three months. The spacecraft instrumentation includes a framing camera, a visual and infrared spectrometer, and a gamma - ray and neutron detector. These instruments will examine Ceres ' shape and elemental composition. On 13 January 2015, Dawn took the first images of Ceres at near - Hubble resolution, revealing impact craters and a small high - albedo spot on the surface, near the same location as that observed previously. Additional imaging sessions, at increasingly better resolution took place on 25 January, 4, 12, 19, and 25 February, 1 March, and 10 and 15 April. Dawn 's arrival in a stable orbit around Ceres was delayed after, close to reaching Ceres, it was hit by a cosmic ray, making it take another, longer route around Ceres in back, instead of a direct spiral towards it. The Chinese Space Agency is designing a sample retrieval mission from Ceres that would take place during the 2020s. Maps Map of Ceres ( red = IR - bright ; green = high albedo areas ; blue = UV - bright ) ( September 2015 ) Map of Ceres ( centered on 180 ° longitude ; color ; March 2015 ) Map of Ceres ( Mercator ; HAMO ; color ; March 2016 ) Map of Ceres ( Elliptical ; HAMO ; color ; March 2016 ) Black - and - white photographic map of Ceres, centered on 0 ° longitude, with official nomenclature ( August 2015 ) Topographic map of Ceres ( September 2016 ). 15 km ( 10 mi ) of elevation separate the lowest crater floors ( indigo ) from the highest peaks ( white ). Hemispheric topographic maps of Ceres, centered on 60 ° and 240 ° east longitude ( July 2015 ). Ceres, polar regions ( November 2015 ) : North ( left ) ; south ( right ). Ceres -- Survey Maps ( June 2015 ) Overall Kerwan section ( PDF version ) Asari - Zadeni section ( PDF version ) Occator section ( PDF version ) Map of quadrangles The following imagemap of the dwarf planet Ceres is divided into 15 quadrangles. They are named after the first craters whose names the IAU approved in July 2015. The map image ( s ) were taken by the Dawn space probe. 90 ° N 180 ° E ﻿ / ﻿ 90 ° N 180 ° E ﻿ / 90 ; 180 0 ° N 0 ° E ﻿ / ﻿ 0 ° N 0 ° E ﻿ / 0 ; 0 0 ° N 180 ° E ﻿ / ﻿ 0 ° N 180 ° E ﻿ / 0 ; 180 North Polar Area Asari Ac - H - 1 Coniraya Ac - H - 2 Dantu Ac - H - 3 Ezinu Ac - H - 4 Fejokoo Ac - H - 5 Haulani Ac - H - 6 Kerwan Ac - H - 7 Nawish Ac - H - 8 Occator Ac - H - 9 Rongo Ac - H - 10 Sintana Ac - H - 11 Toharu Ac - H - 12 Urvara Ac - H - 13 Yalode Ac - H - 14 Zadeni Ac - H - 15 South Polar Area Topographic map of Ceres as of February 2015. Darker areas represent lower elevations, and brighter areas represent higher elevations. ( view talk ) Gallery Ceres in half shadow from 40,000 km ( 25 February 2015 ) Dawn Ceres mosaic -- 19 February 2015 Ceres from Dawn, 47,000 kilometers ( 29,000 mi ) away. At this distance, Ceres is approximately the apparent size of the full moon ( 19 February 2015 ). The large impact basin in the lower portion of the left image appears relatively young. Ceres at 84,000 kilometers ( 52,000 mi ) away ( 12 February 2015 ), at half the apparent size of the full moon. Relative to these images, those at left were taken at similar longitudes but a more northerly latitude, and are rotated approximately 45 ° clockwise. 2004 Hubble Space Telescope 14 April 2015 ; Dawn 22,000 km ( 14,000 mi ) 6 May 2015 ; Dawn 13,600 km ( 8,500 mi ) 16 May 2015 ; Dawn 7,500 km ( 4,700 mi ) ( 1 ; 2 ; 3 ) 22 May 2015 ; Dawn 5,100 km ( 3,200 mi ) ( 1 ; 2 ; 3 ; 4 ; 5 ) ( Ezinu crater : context ; closeup ) Mapping orbits and resolution -- Photos of Ceres by Dawn on Commons Orbit phase No. Dates Altitude ( km ; mi ) Orbital period Resolution ( km / px ) Improvement over Hubble Notes RC3 1st 23 April 2015 -- 9 May 2015 13,500 km ( 8,400 mi ) 15 days 1.3 24 × Survey 2nd 6 June 2015 -- 30 June 2015 4,400 km ( 2,700 mi ) 3.1 days 0.41 73 × HAMO 3rd 17 August 2015 -- 23 October 2015 1,450 km ( 900 mi ) 19 hours 0.14 ( 140 m ) 217 × LAMO / XMO1 4th 16 December 2015 -- 2 September 2016 375 km ( 233 mi ) 5.5 hours 0.035 ( 35 m ) 850 × XMO2 5th 5 October 2016 -- 4 November 2016 1,480 km ( 920 mi ) 19 hours 0.14 ( 140 m ) 217 × XMO3 6th 5 December 2016 -- 7,520 -- 9,350 km ( 4,670 -- 5,810 mi ) ≈ 8 days 0.9 ( est ) 34 × ( est ) 23 April 2015 ; Dawn 1st Map Orbit - RC3 13,600 km ( 8,500 mi ) ( 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8 ; 9 ; 10 ; 11 ; 12 ; 13 ; 14 ; 15 ; 16 ; 17 ; 18 ; 19 ; 20 ; 21 ; 22 ; 23 ; 24 ) ( 3D : 1 ; 5 ; 6 ; 7 ) ( animation ) 6 June 2015 : Dawn 2nd Map Orbit - SRVY 4,400 km ( 2,700 mi ) ( 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8 ; 9 ; 10 ; 11 ; 12 ; 13 ; 14 ; 15 ; 16 ; 17 ; 18 ; 19 ; 20 ; 21 ; 22 ; 23 ; 24 ; 25 ; 26 ; 27 ; 28 ; 29 ; 30 ; 31 ; 32 ; 33 ; 34 ; 35 ; 36 ; 37 ; 38 ; 39 ; 40 ; 41 ; 42 ; 43 ; 44 ; 45 ; 46 ; 47 ; 48 ; 49 ; 50 ; 51 ; 52 ; 53 ; 54 ) 17 August 2015 : Dawn 3rd Map Orbit - HAMO 1,470 km ( 910 mi ) ( 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8 ; 9 ; 10 ; 11 ; 12 ; 13 ; 14 ; 15 ; 16 ; 17 ; 18 ; 19 ; 20 ; 21 ; 22 ; 23 ; 24 ; 25 ; 26 ; 27 ; 28 ; 29 ; 30 ; 31 ; 32 ; 33 ; 34 ; 35 ; 36 ; 37 ; 38 ; 39 ; 40 ; 41 ; 42 ; 43 ; 44 ; 45 ; 46 ; 47 ; 48 ; 49 ; 50 ; 51 ; 52 ; 53 ; 54 ; 55 ; 56 ; 57 ; 58 ; 59 ; 60 ; 61 ; 62 ; 63 ; 64 ; 65 ; 66 ; 67 ; 68 ; 69 ; 70 ; 71 ; 72 ; 73 ; 74 ; 75 ; 76 ; 77 ; 78 ; 79 ; 80 ; 81 ; 82 ; 83 ; 84 ; 85 ; 86 ; 87 ; 88 ; 89 ) 10 Dec 2015 : Dawn 4th Map Orbit - LAMOa 385 km ( 239 mi ) ( a ; b ; c ; d ; e ; 1 ; 2 ; 3 ; 4 ; 5 ; 6 ; 7 ; 8 ; 9 ; 10 ; 11 ; 12 ; 13 ; 14 ; 15 ; 16 ; 17 ; 18 ; 19 ; 20 ; 21 ; 22 ; 23 ; 24 ; 25 ; 26 ; 27 ; 28 ; 29 ; 30 ; 31 ; 32 ; 33 ; 34 ; 35 ; 36 ; 37 ; 38 ; 39 ; 40 ; m1 ; m2 ; m3 ; 41 ; 42 ; 43 ; 44 ; 45 ; 46 ; 47 ; 48 ; 49 ; 50 ; 51 ; 52 ; 53 ; 54 ; 55 ; 56 ; 57 ; 58 ; 59 ; 60 ; 61 ; 62 ; 63 ; 64 ; 65 ; 66 ; 67 ; 68 ; 69 ; 70 ; 71 ; 72 ; 73 ; 74 ; 75 ; 76 ; 77 ; 78 ; 79 ; 80 ; 81 ; 82 ; 83 ) 10 Dec 2015 : Dawn 4th Map Orbit - LAMOb 385 km ( 239 mi ) ( 84 ; 85 ; 86 ; 87 ; 88 ; 89 ; 90 ; 91 ; 92 ; 93 ; 94 ; 95 ; 96 ; 97 ; 98 ; 99 ; 100 ; 101 ; 102 ; 103 ; 104 ; 105 ; 106 ; 107 ; 108 ; 109 ; 110 ; 111 ; 112 ; 113 ; 114 ; 115 ; 116 ; 117 ; 118 ; 119 ; 120 ; 121 ; 122 ; 123 ; 124 ; 125 ; 126 ; 127 ; 128 ; 129 ; 130 ; 131 ; 132 ; 133 ; 134 ; 135 ; 136 ; 137 ; 138 ; 139 ; 140 ; 141 ; 142 ; 143 ; 144 ; 145 ; 146 ; 147 ; 148 ; 149 ) 10 Dec 2015 : Dawn 4th Map Orbit - LAMOc 385 km ( 239 mi ) ( 150 ; 151 ; 152 ; 153 ; 154 ; 155 ; 156 ; 157 ; 158 ; 159 ; 160 ; 161 ; 162 ; 163 ; 164 ; 165 ; 166 ; 167 ; 168 ; 169 ; 170 ; 171 ; 172 ; 173 ; 174 ; 175 ; 176 ; 177 ; 178 ; 179 ; 180 ; 181 ; 182 ; 183 ; 184 ; 185 ; 186 ; 187 ; 188 ; 189 ; 190 ; 191 ; 192 ; 193 ; 194 ; 195 ; 196 ; 197 ; 198 ; 199 ; 200 ; 201 ; 202 ; 203 ; 204 ; 205 ; 206 ; 207 -- end ) True - color images Animations 4 February 2015 ; Dawn 90,000 km ( 56,000 mi ) 29 April 2017 : Dawn 20,000 km ( 12,000 mi ) 4 May 2015 ; Dawn 13,600 km ( 8,500 mi ) 4 May 2015 ; Dawn 13,600 km ( 8,500 mi ) bright spots Ceres flyover animations Play media Surface features exaggerated ( simulated ; 01 : 15 ; 8 June 2015 ) Play media Focus on Occator Crater ( false colors ; 01 : 12 ; 9 December 2015 ) Play media Flight over dwarf planet Ceres ( color ; 03 : 43 ; 29 January 2016 ) Play media Ceres -- Occator Crater -- Flyover ( animation ; 02 : 20 ; 15 December 2016 ) See also Solar System portal Book : Solar System Ceres ( dwarf planet ) in fiction Mining of Ceres Former classification of planets List of exceptional asteroids List of geological features on Ceres List of Solar System objects by size Notes Jump up ^ This image was taken by the Dawn spacecraft on 2 May 2015, during a `` rotation characterization '' orbit, 13,642 kilometres ( 8,477 mi ) above the surface of Ceres. Visible at center and center right are two bright spots, a phenomenon common on Ceres, in Oxo and Haulani craters respectively. Ahuna Mons is also visible in the image as a noticeable, bluff hill, seen just right of bottom. Jump up ^ The value of 0.37 is the mean moment of inertia, which is thought to better represent Ceres ' interior structure than the polar moment of inertia ( 0.39 ), due to the high polar flattening. Jump up ^ Due to its eccentric orbit, the dwarf planet Pluto was also within the orbit of Neptune from 1979 to 1999, and will be again from approximately 2227 to 2247. Jump up ^ All other languages but one use a variant of Ceres / Cerere : Russian Tserera, Persian Seres, Japanese Keresu. The exception is Chinese, which uses ' grain - god ( dess ) star ' ( 穀神星 gǔshénxīng ). Note that this is unlike the goddess Ceres, where Chinese does use the Latin name ( 刻 瑞 斯 kèruìsī ). Jump up ^ In 1807 Klaproth tried to change the name to the more etymologically justified `` cererium '', but it did not catch on. Jump up ^ This emission rate is modest compared to those calculated for the tidally driven plumes of Enceladus ( a smaller body ) and Europa ( a larger body ), 200 kg / s and 7000 kg / s, respectively. References Jump up ^ Schmadel, Lutz ( 2003 ). Dictionary of minor planet names ( 5th ed. ). Germany : Springer. p. 15. ISBN 978 - 3 - 540 - 00238 - 3. ^ Jump up to : Simpson, D.P. ( 1979 ). Cassell 's Latin Dictionary ( 5th ed. ). London : Cassell Ltd. p. 883. ISBN 978 - 0 - 304 - 52257 - 6. Jump up ^ `` The MeanPlane ( Invariable plane ) of the Solar System passing through the barycenter ''. 3 April 2009. Archived from the original on 14 May 2009. Retrieved 10 April 2009. ( produced with Solex 10 Archived 29 April 2009 at WebCite written by Aldo Vitagliano ; see also Invariable plane ) ^ Jump up to : `` 1 Ceres ''. JPL Small - Body Database Browser. 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( 23 January 2014 ). `` Localized sources of water vapour on the dwarf planet ( 1 ) Ceres ''. Nature. 505 ( 7484 ) : 525 -- 527. Bibcode : 2014Natur. 505... 525K. ISSN 0028 - 0836. PMID 24451541. doi : 10.1038 / nature12918. Jump up ^ Campins, H. ; Comfort, C.M. ( 23 January 2014 ). `` Solar system : Evaporating asteroid ''. Nature. 505 ( 7484 ) : 487 -- 488. Bibcode : 2014Natur. 505... 487C. PMID 24451536. doi : 10.1038 / 505487a. Jump up ^ Hansen, C.J. ; Esposito, L. ; Stewart, A.I. ; Colwell, J. ; Hendrix, A. ; Pryor, W. ; Shemansky, D. ; West, R. ( 2006 - 03 - 10 ). `` Enceladus ' Water Vapor Plume ''. Science. 311 ( 5766 ) : 1422 -- 1425. Bibcode : 2006Sci... 311.1422 H. PMID 16527971. doi : 10.1126 / science. 1121254. Jump up ^ Roth, L. ; Saur, J. ; Retherford, K.D. ; Strobel, D.F. ; Feldman, P.D. ; McGrath, M.A. ; Nimmo, F. ( 26 November 2013 ). `` Transient Water Vapor at Europa 's South Pole '' ( PDF ). Science. 343 ( 6167 ) : 171 -- 174. Bibcode : 2014Sci... 343... 171R. PMID 24336567. doi : 10.1126 / science. 1247051. Retrieved 26 January 2014. Jump up ^ Arizona State University ( 1 September 2016 ). `` Ceres : The tiny world where volcanoes erupt ice ''. ScienceDaily. Retrieved 8 March 2017. Jump up ^ Hiesinger, H. ; Marchi, S. ; Schmedemann, N. ; Schenk, P. ; Pasckert, J.H. ; Neesemann, A. ; OBrien, D.P. ; Kneissl, T. ; Ermakov, A.I. ; Fu, R.R. ; Bland, M.T. ; Nathues, A. ; Platz, T. ; Williams, D.A. ; Jaumann, R. ; Castillo - Rogez, J.C. ; Ruesch, O. ; Schmidt, B. ; Park, R.S. ; Preusker, F. ; Buczkowski, D.L. ; Russell, C.T. ; Raymond, C.A. ( 1 September 2016 ). `` Cratering on Ceres : Implications for its crust and evolution ''. Science. 353 ( 6303 ) : aaf4759. Bibcode : 2016Sci... 353.4759 H. doi : 10.1126 / science. aaf4759. Jump up ^ NASA / Jet Propulsion Laboratory ( 1 September 2016 ). `` Ceres ' geological activity, ice revealed in new research ''. ScienceDaily. Retrieved 8 March 2017. 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Science. 277 ( 5331 ) : 1492 -- 1495. Bibcode : 1997Sci... 277.1492 T. doi : 10.1126 / science. 277.5331. 1492. CS1 maint : Multiple names : authors list ( link ) Jump up ^ Wall, Mike ( 2 September 2016 ). `` NASA 's Dawn Mission Spies Ice Volcanoes on Ceres ''. Scientific American. Retrieved 8 March 2017. ^ Jump up to : 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. Retrieved 25 June 2009. CS1 maint : Multiple names : authors list ( link ) Jump up ^ Wall, Mike ( 27 July 2014 ). `` Strange Bright Spots on Ceres Create Mini-Atmosphere on Dwarf Planet ''. Space.com. Retrieved 2015 - 08 - 03. Jump up ^ Catling, David C. ( 2013 ). Astrobiology : A Very Short Introduction. Oxford : Oxford University Press. p. 99. ISBN 0 - 19 - 958645 - 4. Jump up ^ Castillo - Rogez, J.C. ; Conrad, P.G. ( 2010 ). Habitability Potential of Ceres, a Warm Icy Body in the Asteroid Belt ( PDF ). LPI Conference 2010. Lunar and Planetary Institute. Jump up ^ Hand, Eric ( 20 February 2015 ). `` Dawn probe to look for a habitable ocean on Ceres ''. Science. 347 ( 6224 ) : 813 -- 814. Bibcode : 2015Sci... 347... 813H. PMID 25700494. doi : 10.1126 / science. 347.6224. 813. Retrieved 2015 - 09 - 16. Jump up ^ Houtkooper, Joop M. ; `` Glaciopanspermia : Seeding the Terrestrial Planets with Life ? '' Archived 22 July 2011 at the Wayback Machine. Institute for Psychobiology and Behavioral Medicine, Justus - Liebig - University, Giessen, Germany Jump up ^ O'Neill, Ian ( 5 March 2009 ). `` Life on Ceres : Could the Dwarf Planet be the Root of Panspermia ''. Universe Today. Retrieved 30 January 2012. Jump up ^ `` SPHERE Maps the Surface of Ceres ''. Retrieved 8 September 2015. Jump up ^ Martinez, Patrick, The Observer 's Guide to Astronomy, page 298. Published 1994 by Cambridge University Press Jump up ^ 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 ° 471 ''. Icarus. 72 ( 3 ) : 507 -- 518. Bibcode : 1987Icar... 72... 507M. doi : 10.1016 / 0019 - 1035 ( 87 ) 90048 - 0. CS1 maint : Multiple names : authors list ( link ) Jump up ^ `` Observations reveal curiosities on the surface of asteroid Ceres ''. Archived from the original on 5 October 2011. Retrieved 16 August 2006. ^ Jump up to : `` Asteroid Occultation Updates ''. Asteroidoccultation.com. 22 December 2012. Archived from the original on 2012 - 07 - 12. Retrieved 20 August 2013. Jump up ^ `` Water Detected on Dwarf Planet Ceres ''. Science.nasa.gov. Retrieved 24 January 2014. Jump up ^ Ulivi, Paolo ; Harland, David ( 2008 ). Robotic Exploration of the Solar System : Hiatus and Renewal, 1983 -- 1996. Springer Praxis Books in Space Exploration. Springer. pp. 117 -- 125. 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Retrieved 18 March 2015. Jump up ^ China 's Deep - space Exploration to 2030 by Zou Yongliao Li Wei Ouyang Ziyuan Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing Jump up ^ Landau, Elizabeth ( 28 July 2015 ). `` New Names and Insights at Ceres ''. NASA. Retrieved 28 July 2015. Jump up ^ Staff ( 17 July 2015 ). `` First 17 Names Approved for Features on Ceres ''. USGS. Retrieved 9 August 2015. Jump up ^ Rayman, Marc ( 25 February 2015 ). `` Dawn Journal : Ceres ' Deepening Mysteries ''. Planetary Society. Retrieved 25 February 2015. Jump up ^ Krummheuer, B. ( 25 February 2015 ). `` Dawn : Two new glimpses of dwarf planet Ceres ''. Max Planck Institute for Solar System Research. Retrieved 26 February 2015. Jump up ^ Rayman, Marc ( 31 March 2015 ). `` Dawn Journal March 31 ( 2015 ) ''. NASA / Jet Propulsion Laboratory. Retrieved 9 September 2015. Jump up ^ Rayman, Marc ( 30 July 2015 ). `` Dawn Journal : Descent to HAMO ''. The Planetary Society. Retrieved 9 September 2015. Jump up ^ `` PIA21221 : Dawn XMO2 Image 1 ''. NASA / Jet Propulsion Laboratory. 7 November 2016. Retrieved 20 November 2016. ^ Jump up to : `` Dawn Mission Status Updates ''. NASA / Jet Propulsion Laboratory. 16 October 2015. Retrieved 17 October 2015. Jump up ^ Rayman, Marc D. ( 28 November 2016 ). `` Dawn Journal ''. NASA / JPL. Retrieved 8 March 2017. Jump up ^ Landau, Elizabeth ; Dyches, Preston ( 8 June 2015 ). `` Fly Over Ceres in New Video ''. NASA. Retrieved 9 June 2015. External links Wikimedia Commons has media related to Ceres ( dwarf planet ). Destination Ceres : Breakfast at Dawn -- NASA Dawn mission home page at JPL A simulation of the orbit of Ceres JPL Ephemeris How Gauss determined the orbit of Ceres from keplersdiscovery.com Hilton, James L. ( 1999 ). `` U.S. Naval Observatory Ephemerides of the Largest Asteroids ''. The Astronomical Journal. 117 ( 2 ) : 1077 -- 1086. Bibcode : 1999AJ... 117.1077 H. doi : 10.1086 / 300728. Animated reprojected colorized map of Ceres ( 22 February 2015 ) Rotating relief model of Ceres by Seán Doran ( about 60 % of a full rotation ; starts with Occator midway above center ) Ceres Geography General Geology of Ceres Craters Achita Annona Asari Coniraya Dantu Darzamat Ezinu Fejokoo Hamori Haulani Kerwan Mondamin Nawish Occator Urvara Yalode Zadeni Montes Ahuna Mons Other features Bright spots Astronomy Classification Asteroid Definition of planet Dwarf planet Planet 2006 definition of planet Discovery Barnaba Oriani Carl Friedrich Gauss Francis Wollaston Franz Xaver von Zach Giuseppe Piazzi Heinrich Olbers Jérôme Lalande Johann Elert Bode Tobias Mayer Possible trojans ( 185105 ) 2006 SV 23 1372 Haremari Exploration Dawn mission Ceres Polar Lander ( proposed ) Related Ceres in fiction Colonization In astrology Solar System bodies formerly considered to be planets Dwarf planets Asteroid belt IAU : Ceres No longer rounded and therefore not dwarf planets ( Former candidates : Pallas Vesta Hygiea ) Centaurs Possibly : Chariklo Chiron Centaurs ( extended ) Possibly : 1995 SN 55 ( lost ) Ceto 2010 TY 53 Plutinos IAU : Pluto Additional objects proposed by Brown and Tancredi : Orcus Ixion 2003 AZ 2004 UX Huya Possibly : 2003 UZ 2003 VS 2002 VR 2004 PF 2002 XV 93 2007 JH 43 2001 QF 298 Twotinos Possibly : 2002 WC Other resonances / unknown resonances : IAU : Haumea Possibly : 2002 XW 1999 DE 1999 KR 2001 YH 2011 GM 27 2010 VK 201 2013 FZ 27 2014 UM 33 1999 CD 158 Cubewanos : IAU : Makemake Additional objects proposed by Brown and Tancredi : 2002 MS Salacia Quaoar Varuna Varda 2004 GV 2002 AW 2002 TX 2005 RR 2003 OP 2005 RN Possibly : Chaos Altjira Sila - Nunam 2002 UX 2007 JJ 2005 UQ 2004 TY 2003 QW 1998 SN 2002 KX Praamzius 2004 NT 2010 FX 86 2002 CY 248 2010 VR 11 Rhadamanthus Scattered disc IAU : Eris Additional objects proposed by Brown and Tancredi : 2007 OR 1996 TL 2001 UR 2005 RM Possibly : 2002 TC 2004 XA 2005 QU 2006 QH 181 2007 UK 2010 EK 139 2010 KZ 39 2010 RE 64 2010 RF 43 2010 TJ 2013 FY 27 2008 OG 19 1996 GQ 2012 HH 1999 CC 2010 VZ 98 Area uncertain Captured satellites that were once dwarf planets : Triton ( captured by Neptune ) Phoebe ( captured by Saturn, and no longer rounded ) Possibly : 2011 FW 62 ( lost ) 2000 YW V774104 Detached objects Possibly : 2004 XR 190 2010 GB 174 2008 ST 291 1995 TL 2005 TB 2003 QX 113 2003 FY 2004 VN 112 2000 CR Sednoids Objects proposed by Brown and Tancredi : Sedna Possibly : 2012 VP 113 See also : Charon Vanth Dysnomia Hiʻiaka Mesoplanet Planemo List of trans - Neptunian objects List of possible dwarf planets List of Solar System objects List of Solar System objects by size Large asteroids ( over 200 km in diameter ) Asteroids over 500 km Dwarf planets Ceres Disrupted dwarf planets Vesta Irregular asteroids Pallas Asteroids between 300 and 500 km Hygiea Europa Interamnia Asteroids between 200 and 300 km Davida Sylvia Cybele Eunomia Juno Euphrosyne Psyche Hektor Thisbe Bamberga Patientia Herculina Doris Ursula Camilla Eugenia Iris Amphitrite Diotima Fortuna Egeria Aurora The Solar System The Sun Mercury Venus Earth Mars Ceres Jupiter Saturn Uranus Neptune Pluto Haumea Makemake Eris Planets Terrestrial planets Mercury Venus Earth Mars Giant planets Jupiter Saturn Uranus Neptune Dwarf planets Ceres Pluto Haumea Makemake Eris Rings Jovian Saturnian ( Rhean ) Charikloan Chironean Uranian Neptunian Moons 1 Terrestrial ( Moon ) Other near - Earth objects 2 Martian Phobos Deimos 69 Jovian Ganymede Callisto Io Europa all 62 Saturnian Titan Rhea Iapetus Dione Tethys Enceladus Mimas Hyperion Phoebe all 27 Uranian Titania Oberon Umbriel Ariel Miranda all 14 Neptunian Triton Proteus Nereid all 5 Plutonian Charon Nix Hydra Kerberos Styx 2 Haumean Hiʻiaka Namaka 1 Makemakean ( S / 2015 ( 136472 ) 1 ) 1 Eridian ( Dysnomia ) Lists Solar System objects By size By discovery date Minor planets Gravitationally rounded objects Possible dwarf planets Natural satellites Comets Small Solar System bodies Meteoroids Minor planets moons Comets Damocloids Mercury - crossers Venus - crossers Venus trojans Near - Earth objects Earth - crossers Earth trojans Mars - crossers Mars trojans Asteroid belt Asteroids first discovered : Ceres Pallas Juno Vesta Families Notable asteroids Kirkwood gap Main - belt comets Jupiter trojans Jupiter - crossers Centaurs Saturn - crossers Uranus trojans Uranus - crossers Neptune trojans Cis - Neptunian objects Trans - Neptunian objects Neptune - crossers Plutoids Kuiper belt Plutinos Cubewanos Scattered disc Detached objects Sednoids Hills cloud Oort cloud Hypothetical objects Vulcan Vulcanoids Phaeton Planet V Theia Fifth giant Planets beyond Neptune Tyche Nemesis Planet Nine Exploration ( outline ) Discovery Astronomy Timeline Spaceflight Robotic spacecraft Human spaceflight Colonization List of probes Timeline Mercury Venus Moon Mars Ceres Asteroids Mining Comets Jupiter Saturn Uranus Neptune Pluto Deep space Outline of the Solar System Portals Solar System Astronomy Earth sciences Mars Jupiter Uranus Cosmology Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Virgo Supercluster → Laniakea Supercluster → Observable universe → Universe Each arrow ( → ) may be read as `` within '' or `` part of ''. Minor planets navigator 1 Ceres 2 Pallas Authority control WorldCat Identities VIAF : 61145067201766630857 LCCN : sh85022130 GND : 4742216 - 6 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Ceres_(dwarf_planet)&oldid=797637301 '' Categories : Ceres ( dwarf planet ) Main - belt asteroids Numbered minor planets Discoveries by Giuseppe Piazzi Minor planets named from Roman mythology Named minor planets Minor planets visited by spacecraft C - type asteroids ( SMASS ) G - type asteroids ( Tholen ) Astronomical objects discovered in 1801 Hidden categories : Webarchive template webcite links CS1 maint : Multiple names : authors list CS1 maint : Explicit use of et al. 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Question: how long does it take ceres to orbit the sun
Answer: 4.6 Earth years