Ceres (dwarf planet) explained

Minorplanet:yes
Background:
  1. D6D6D6
1 Ceres
Symbol: (historically astronomical, now mostly astrological)
Discovery Ref:[1]
Discoverer:Giuseppe Piazzi
Discovered:1 January 1801
Mpc Name:1 Ceres
Pronounced:,
Named After:Cerēs
Adjectives:Cererian, -ean
Epoch:21 January 2022 (JD 2459600.5)
Aphelion:NaN2.98318
Perihelion:NaN2.54891
Time Periastron:7 December 2022
Semimajor:NaN2.76604
P Orbit Ref:[2]
Satellites:None
Allsatellites:yes
Dimensions:(966.2 × 962.0 × 891.8)
± 0.2 km[3]
Density:[4]
Moment Of Inertia Factor:[5]
Escape Velocity: km/s
Right Asc North Pole:291.42744°[6]
Declination:66.76033°[7]
Axial Tilt:≈4°
Temp Name1:Kelvin
Min Temp 1:≈110
Max Temp 1:235±4[8]
Spectral Type:C[9]
Angular Size:0.854″ to 0.339″

Ceres (minor-planet designation: 1 Ceres) is a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter. It was the first known asteroid, discovered on 1 January 1801 by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily, and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planet, the only one not beyond Neptune's orbit.

Ceres's small size means that even at its brightest it is too dim to be seen by the naked eye, except under extremely dark skies. Its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition (when it is closest to Earth) once every 15- to 16-month synodic period. As a result, its surface features are barely visible even with the most powerful telescopes, and little was known about it until the robotic NASA spacecraft Dawn approached Ceres for its orbital mission in 2015.

Dawn found Ceres's surface to be a mixture of water ice and hydrated minerals such as carbonates and clay. Gravity data suggest Ceres to be partially differentiated into a muddy (ice-rock) mantle/core and a less dense but stronger crust that is at most thirty per cent ice by volume. Although Ceres likely lacks an internal ocean of liquid water, brines still flow through the outer mantle and reach the surface, allowing cryovolcanoes such as Ahuna Mons to form roughly every fifty million years. This makes Ceres the closest known cryovolcanically active body to the Sun. Additionally, Ceres hosts an extremely tenuous and transient atmosphere of water vapour, vented from localised sources on its surface.

History

Discovery

In the years between the acceptance of heliocentrism in the 18th century and the discovery of Neptune in 1846, several astronomers argued that mathematical laws predicted the existence of a hidden or missing planet between the orbits of Mars and Jupiter. In 1596, theoretical astronomer Johannes Kepler believed that the ratios between planetary orbits would conform to "God's design" only with the addition of two planets: one between Jupiter and Mars and one between Venus and Mercury. Other theoreticians, such as Immanuel Kant, pondered whether the gap had been created by the gravity of Jupiter; in 1761, astronomer and mathematician Johann Heinrich Lambert asked: "And who knows whether already planets are missing which have departed from the vast space between Mars and Jupiter? Does it then hold of celestial bodies as well as of the Earth, that the stronger chafe the weaker, and are Jupiter and Saturn destined to plunder forever?"

In 1772, German astronomer Johann Elert Bode, citing Johann Daniel Titius, published a formula later known as the Titius–Bode law that appeared to predict the orbits of the known planets but for an unexplained gap between Mars and Jupiter.[10] This formula predicted that there ought to be another planet with an orbital radius near 2.8 astronomical units (AU), or 420millionkm, from the Sun. The Titius–Bode law gained more credence with William Herschel's 1781 discovery of Uranus near the predicted distance for a planet beyond Saturn. In 1800, a group headed by Franz Xaver von Zach, editor of the German astronomical journal German: {{ill|Monatliche Correspondenz|de (Monthly Correspondence), 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 the asteroids Pallas, Juno, and Vesta.

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.[11] 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".[12] Instead of a star, Piazzi had found a moving starlike object, which he first thought was a comet.[13] Piazzi observed Ceres twenty-four times, the final sighting occurring on 11 February 1801, when illness interrupted his work. He announced his discovery on 24 January 1801 in letters to two fellow astronomers, his compatriot Barnaba Oriani of Milan and Bode in Berlin.[14] 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 French astronomer Jérôme Lalande. The information was published in the September 1801 issue of the German: Monatliche Correspondenz.

By this time, the apparent position of Ceres had changed (primarily due to Earth's motion around the Sun) and was too close to the Sun's glare for other astronomers to confirm Piazzi's observations. Towards 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, mathematician Carl Friedrich Gauss, then twenty-four years old, developed an efficient method of orbit determination. He predicted the path of Ceres within a few weeks and sent his results to von Zach. On 31 December 1801, von Zach and fellow celestial policeman Heinrich W. M. Olbers found Ceres near the predicted position and continued to record its position. At 2.8 AU from the Sun, Ceres appeared to fit the Titius–Bode law almost perfectly; when Neptune was discovered in 1846, eight AU closer than predicted, most astronomers concluded that the law was a coincidence.[15]

The early observers were able to calculate the size of Ceres only to within an order of magnitude. Herschel underestimated its diameter at in 1802; in 1811, German astronomer Johann Hieronymus Schröter overestimated it as .[16] In the 1970s, infrared photometry enabled more accurate measurements of its albedo, and Ceres's diameter was determined to within ten per cent of its true value of .

Name and symbol

Piazzi's proposed name for his discovery was Ceres Ferdinandea: Ceres after the Roman goddess of agriculture, whose earthly home, and oldest temple, lay in Sicily; and Ferdinandea in honour of Piazzi's monarch and patron, King FerdinandIII of Sicily. The latter was not acceptable to other nations and was dropped. Before von Zach's recovery of Ceres in December 1801, von Zach referred to the planet as Hera, and Bode referred to it as Juno. Despite Piazzi's objections, those names gained currency in Germany before the object's existence was confirmed. Once it was, astronomers settled on Piazzi's name.[17]

The adjectival forms of Ceres are Cererian[18] [19] and Cererean,[20] both pronounced .[21] [22] Cerium, a rare-earth element discovered in 1803, was named after the dwarf planet Ceres.[23]

The old astronomical symbol of Ceres, still used in astrology, is a sickle, .[24] The sickle was one of the classical symbols of the goddess Ceres and was suggested, apparently independently, by von Zach and Bode in 1802.[25] It is similar in form to the symbol (♀) (a circle with a small cross beneath) of the planet Venus, but with a break in the circle. It had various minor graphic variants, including a reversed form typeset as a 'C' (the initial letter of the name Ceres) with a plus sign. The generic asteroid symbol of a numbered disk, ①, was introduced in 1867 and quickly became the norm.[26]

Classification

See main article: Geology of Ceres.

The categorisation of Ceres has changed more than once and has been the subject of some disagreement. Bode believed Ceres to be the "missing planet" he had proposed to exist between Mars and Jupiter. Ceres was assigned a planetary symbol and remained listed as a planet in astronomy books and tables (along with Pallas, Juno, and Vesta) for over half a century.

As other objects were discovered in the neighbourhood of Ceres, astronomers began to suspect that it represented the first of a new class of objects. When Pallas was discovered in 1802, Herschel coined the term asteroid ("star-like") for these bodies,[27] writing that "they resemble small stars so much as hardly to be distinguished from them, even by very good telescopes".[28] In 1852 Johann Franz Encke, in the Berliner Astronomisches Jahrbuch, declared the traditional system of granting planetary symbols too cumbersome for these new objects and introduced a new method of placing numbers before their names in order of discovery. The numbering system initially began with the fifth asteroid, 5 Astraea, as number1, but in 1867, Ceres was adopted into the new system under the name 1Ceres.

By the 1860s, astronomers widely accepted that a fundamental difference existed between the major planets and asteroids such as Ceres, though the word "planet" had yet to be precisely defined. In the 1950s, scientists generally stopped considering most asteroids as planets, but Ceres sometimes retained its status after that because of its planet-like geophysical complexity.[29] Then, in 2006, the debate surrounding Pluto led to calls for a definition of "planet", and the possible reclassification of Ceres, perhaps even its general reinstatement as a planet.[30] A proposal before the International Astronomical Union (IAU), the global body responsible for astronomical nomenclature and classification, 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".[31] Had this resolution been adopted, it would have made Ceres the fifth planet in order from the Sun,[32] but on 24 August 2006 the assembly adopted the additional requirement that a planet must have "cleared the neighbourhood around its orbit". 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 forty per cent of the belt's total mass.[33] Bodies that met the first proposed definition but not the second, such as Ceres, were instead classified as dwarf planets.[34] Planetary geologists still often ignore this definition and consider Ceres to be a planet anyway.[35]

Ceres is a dwarf planet, but there is some confusion about whether it is also an asteroid. A NASA webpage states that Vesta, the belt's second-largest object, is the largest asteroid.[36] The IAU has been equivocal on the subject,[37] [38] though its Minor Planet Center, the organisation charged with cataloguing such objects, notes that dwarf planets may have dual designations,[39] and the joint IAU/USGS/NASA Gazetteer categorises Ceres as both asteroid and a dwarf planet.[40]

Orbit

Ceres follows an orbit between Mars and Jupiter, near the middle of the asteroid belt, with an orbital period (year) of 4.6 Earth years. Compared to other planets and dwarf planets, Ceres's orbit is moderately tilted relative to that of Earth; its inclination (i) is 10.6°, compared to 7° for Mercury and 17° for Pluto. It is also slightly elongated, with an eccentricity (e) = 0.08, compared to 0.09 for Mars.

Ceres is not part of an asteroid family, probably due to its large proportion of ice, as smaller bodies with the same composition would have sublimated to nothing over the age of the Solar System. It was once thought to be a member of the Gefion family,[41] the members of which share similar proper orbital elements, suggesting a common origin through an asteroid collision in the past. Ceres was later found to have a different composition from the Gefion family and appears to be an interloper, having similar orbital elements but not a common origin.[42]

Resonances

Due to their small masses and large separations, objects within the asteroid belt rarely fall into gravitational resonances with each other.[43] Nevertheless, Ceres is able to capture other asteroids into temporary 1:1 resonances (making them temporary trojans), for periods from a few hundred thousand to more than two million years. Fifty such objects have been identified.[44] Ceres is close to a 1:1 mean-motion orbital resonance with Pallas (their proper orbital periods differ by 0.2%), but not close enough to be significant over astronomical timescales.[45]

Rotation and axial tilt

The rotation period of Ceres (the Cererian day) is 9hours and 4minutes; the small equatorial crater of Kait is selected as its prime meridian.[46] Ceres has an axial tilt of 4°, small enough for its polar regions to contain permanently shadowed craters that are expected to act as cold traps and accumulate water ice over time, similar to what occurs 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 three times before escaping or being trapped.[47]

Dawn, the first spacecraft to orbit Ceres, determined that the north polar axis points at right ascension 19h 25m 40.3s (291.418°), declination +66° 45' 50" (about 1.5 degrees from Delta Draconis), which means an axial tilt of 4°. This means that Ceres currently sees little to no seasonal variation in sunlight by latitude.[48] Gravitational influence from Jupiter and Saturn over the course of three million years has triggered cyclical shifts in Ceres's axial tilt, ranging from two to twenty degrees, meaning that seasonal variation in sun exposure has occurred in the past, with the last period of seasonal activity estimated at 14,000 years ago. Those craters that remain in shadow during periods of maximum axial tilt are the most likely to retain water ice from eruptions or cometary impacts over the age of the Solar System.[49]

Geology

See main article: Geology of Ceres and List of geological features on Ceres.

Ceres is the largest asteroid in the main asteroid belt. It has been classified as a Ctype or carbonaceous asteroid and, due to the presence of clay minerals, as a G-type asteroid. It has a similar, but not identical, composition to that of carbonaceous chondrite meteorites.[50] It is an oblate spheroid, with an equatorial diameter 8% larger than its polar diameter. Measurements from the Dawn spacecraft found a mean diameter of 939.4km (583.7miles) and a mass of .[51] This gives Ceres a density of, suggesting that a quarter of its mass is water ice.[52]

Ceres makes up 40% of the estimated mass of the asteroid belt, and it has times the mass of the next asteroid, Vesta, but it is only 1.3% the mass of the Moon. It is close to being in hydrostatic equilibrium, but some deviations from an equilibrium shape have yet to be explained.[53] Regardless, Ceres is the only widely accepted dwarf planet with an orbital period less than that of Neptune. Modelling has suggested Ceres's rocky material is partially differentiated, and that it may possess a small core,[54] [55] but the data is also consistent with a mantle of hydrated silicates and no core. Because Dawn lacked a magnetometer, it is not known if Ceres has a magnetic field; it is believed not to.[56] [57] Ceres's internal differentiation may be related to its lack of a natural satellite, as satellites of main belt asteroids are mostly believed to form from collisional disruption, creating an undifferentiated, rubble pile structure.[58]

Surface

Composition

The surface composition of Ceres is homogeneous on a global scale, and it is rich in carbonates and ammoniated phyllosilicates that have been altered by water, though water ice in the regolith varies from approximately 10% in polar latitudes to much drier, even ice-free, in the equatorial regions.

Studies using the Hubble Space Telescope show graphite, sulfur, and sulfur dioxide on Ceres's surface. The graphite is evidently the result of space weathering on Ceres's older surfaces; the latter two are volatile under Cererian conditions and would be expected to either escape quickly or settle in cold traps, and so are evidently associated with areas with relatively recent geological activity.[59]

Organic compounds were detected in Ernutet Crater,[60] and most of the planet's near surface is rich in carbon, at approximately 20% by mass.[61] The carbon content is more than five times higher than in carbonaceous chondrite meteorites analysed on Earth. The surface carbon shows evidence of being mixed with products of rock-water interactions, such as clays. This chemistry suggests Ceres formed in a cold environment, perhaps outside the orbit of Jupiter, and that it accreted from ultra-carbon-rich materials in the presence of water, which could provide conditions favourable to organic chemistry.

Craters

Dawn revealed that Ceres has a heavily cratered surface, though with fewer large craters than expected. Models based on the formation of the current asteroid belt had predicted Ceres should have ten to fifteen craters larger than 400km (200miles) in diameter.[62] The largest confirmed crater on Ceres, Kerwan Basin, is 284km (176miles) across. The most likely reason for this is viscous relaxation of the crust slowly flattening out larger impacts.[63]

Ceres's north polar region shows far more cratering than the equatorial region, with the eastern equatorial region in particular comparatively lightly cratered. The overall size frequency of craters of between twenty and a hundred kilometres (10–60mi) is consistent with their having originated in the Late Heavy Bombardment, with craters outside the ancient polar regions likely erased by early cryovolcanism.[64] Three large shallow basins (planitiae) with degraded rims are likely to be eroded craters. The largest, Vendimia Planitia, at 800km (500miles) across, is also the largest single geographical feature on Ceres.[65] Two of the three have higher than average ammonium concentrations.

Dawn observed 4,423 boulders larger than 105m (344feet) in diameter on the surface of Ceres. These boulders likely formed through impacts, and are found within or near craters, though not all craters contain boulders. Large boulders are more numerous at higher latitudes. Boulders on Ceres are brittle and degrade rapidly due to thermal stress (at dawn and dusk, the surface temperature changes rapidly) and meteoritic impacts. Their maximum age is estimated to be 150million years, much shorter than the lifetime of boulders on Vesta.[66]

Tectonic features

Although Ceres lacks plate tectonics,[67] with the vast majority of its surface features linked either to impacts or to cryovolcanic activity, several potentially tectonic features have been tentatively identified on its surface, particularly in its eastern hemisphere. The Samhain Catenae, kilometre-scale linear fractures on Ceres's surface, lack any apparent link to impacts and bear a stronger resemblance to pit crater chains, which are indicative of buried normal faults. Also, several craters on Ceres have shallow, fractured floors consistent with cryomagmatic intrusion.[68]

Cryovolcanism

See main article: Bright spots on Ceres.

Ceres has one prominent mountain, Ahuna Mons; this appears to be a cryovolcano and has few craters, suggesting a maximum age of 240million years. Its relatively high gravitational field suggests it is dense, and thus composed more of rock than ice, and that its placement is likely due to diapirism of a slurry of brine and silicate particles from the top of the mantle. It is roughly antipodal to Kerwan Basin. Seismic energy from the Kerwan-forming impact may have focused on the opposite side of Ceres, fracturing the outer layers of the crust and triggering the movement of high-viscosity cryomagma (muddy water ice softened by its content of salts) onto the surface.[69] Kerwan too shows evidence of the effects of liquid water due to impact-melting of subsurface ice.[70]

A 2018 computer simulation suggests that cryovolcanoes on Ceres, once formed, recede due to viscous relaxation over several hundred million years. The team identified 22 features as strong candidates for relaxed cryovolcanoes on Ceres's surface.[71] [72] Yamor Mons, an ancient, impact-cratered peak, resembles Ahuna Mons despite being much older, due to it lying in Ceres's northern polar region, where lower temperatures prevent viscous relaxation of the crust. Models suggest that, over the past billion years, one cryovolcano has formed on Ceres on average every fifty million years.[73] The eruptions may be linked to ancient impact basins but are not uniformly distributed over Ceres. The model suggests that, contrary to findings at Ahuna Mons, Cererian cryovolcanoes must be composed of far less dense material than average for Ceres's crust, or the observed viscous relaxation could not occur.

An unexpectedly large number of Cererian craters have central pits, perhaps due to cryovolcanic processes; others have central peaks.[74] Hundreds of bright spots (faculae) have been observed by Dawn, the brightest in the middle of 80km (50miles) Occator Crater.[75] The bright spot in the centre of Occator is named Cerealia Facula, and the group of bright spots to its east, Vinalia Faculae. Occator possesses a pit 9–10 km wide, partially filled by a central dome. The dome post-dates the faculae and is likely due to freezing of a subterranean reservoir, comparable to pingos in Earth's Arctic region.[76] [77] A haze periodically appears above Cerealia, supporting the hypothesis that some sort of outgassing or sublimating ice formed the bright spots.[78] In March 2016 Dawn found definitive evidence of water ice on the surface of Ceres at Oxo crater.[79]

On 9 December 2015, NASA scientists reported that the bright spots on Ceres may be due to a type of salt from evaporated brine containing magnesium sulfate hexahydrate (MgSO4·6H2O); the spots were also found to be associated with ammonia-rich clays. Near-infrared spectra of these bright areas were reported in 2017 to be consistent with a large amount of sodium carbonate and smaller amounts of ammonium chloride or ammonium bicarbonate .[80] [81] These materials have been suggested to originate from the crystallisation of brines that reached the surface.[82] In August 2020 NASA confirmed that Ceres was a water-rich body with a deep reservoir of brine that percolated to the surface in hundreds of locations[83] causing "bright spots", including those in Occator Crater.[84]

Internal structure

The active geology of Ceres is driven by ice and brines. Water leached from rock is estimated to possess a salinity of around 5%. Altogether, Ceres is approximately 50% water by volume (compared to 0.1% for Earth) and 73% rock by mass.[85]

Ceres's largest craters are several kilometres deep, inconsistent with an ice-rich shallow subsurface. The fact that the surface has preserved craters almost 300km (200miles) in diameter indicates that the outermost layer of Ceres is roughly 1000 times stronger than water ice. This is consistent with a mixture of silicates, hydrated salts and methane clathrates, with no more than 30% water ice by volume.[86]

Gravity measurements from Dawn have generated three competing models for Ceres's interior. In the three-layer model, Ceres is thought to consist of an outer, 40km (30miles) thick crust of ice, salts and hydrated minerals and an inner muddy "mantle" of hydrated rock, such as clays, separated by a 60km (40miles) layer of a muddy mixture of brine and rock.[87] It is not possible to tell if Ceres's deep interior contains liquid or a core of dense material rich in metal,[88] but the low central density suggests it may retain about 10% porosity.One study estimated the densities of the core and mantle/crust to be 2.46–2.90 and 1.68–1.95g/cm3 respectively, with the mantle and crust together being 70- thick. Only partial dehydration (expulsion of ice) from the core is expected, though the high density of the mantle relative to water ice reflects its enrichment in silicates and salts.[89] That is, the core (if it exists), the mantle and crust all consist of rock and ice, though in different ratios.

Ceres's mineral composition can be determined (indirectly) only for its outer 100km (100miles). The solid outer crust, 40km (30miles) thick, is a mixture of ice, salts, and hydrated minerals. Under that is a layer that may contain a small amount of brine. This extends to a depth of at least the 100adj=on-1adj=on limit of detection. Under that is thought to be a mantle dominated by hydrated rocks such as clays.

In one two-layer model, Ceres consists of a core of chondrules and a mantle of mixed ice and micron-sized solid particulates ("mud"). Sublimation of ice at the surface would leave a deposit of hydrated particulates perhaps twenty metres thick. The range of the extent of differentiation is consistent with the data, from a large, 360km (220miles) core of 75% chondrules and 25% particulates and a mantle of 75% ice and 25% particulates, to a small, 85round=5NaNround=5 core consisting nearly entirely of particulates and a mantle of 30% ice and 70% particulates. With a large core, the core–mantle boundary should be warm enough for pockets of brine. With a small core, the mantle should remain liquid below 110km (70miles). In the latter case a 2% freezing of the liquid reservoir would compress the liquid enough to force some to the surface, producing cryovolcanism.[90]

A second two-layer model suggests a partial differentiation of Ceres into a volatile-rich crust and a denser mantle of hydrated silicates. A range of densities for the crust and mantle can be calculated from the types of meteorite thought to have impacted Ceres. With CI-class meteorites (density 2.46 g/cm3), the crust would be approximately 70km (40miles) thick and have a density of 1.68 g/cm3; with CM-class meteorites (density 2.9 g/cm3), the crust would be approximately 190km (120miles) thick and have a density of 1.9 g/cm3. Best-fit modelling yields a crust approximately 40km (30miles) thick with a density of approximately 1.25 g/cm3, and a mantle/core density of approximately 2.4 g/cm3.

Atmosphere

In 2017, Dawn confirmed that Ceres has a transient atmosphere of water vapour.[91] Hints of an atmosphere had appeared in early 2014, when the Herschel Space Observatory detected localised mid-latitude sources of water vapour on Ceres, no more than 60km (40miles) in diameter, which each give off approximately molecules (3kg) of water per second.[92] [93] Two potential source regions, designated Piazzi (123°E, 21°N) and Region A (231°E, 23°N), were visualised in the near infrared as dark areas (Region A also has a bright centre) by the Keck Observatory. Possible mechanisms for the vapour release are sublimation from approximately 0.6km2 of exposed surface ice, cryovolcanic eruptions resulting from radiogenic internal heat, or pressurisation of a subsurface ocean due to thickening of an overlying layer of ice.[94] In 2015, David Jewitt included Ceres in his list of active asteroids.[95] Surface water ice is unstable at distances less than 5 AU from the Sun,[96] so it is expected to sublime if exposed directly to solar radiation. Proton emission from solar flares and CMEs can sputter exposed ice patches on the surface, leading to a positive correlation between detections of water vapour and solar activity.[97] Water ice can migrate from the deep layers of Ceres to the surface, but it escapes in a short time. Surface sublimation would be expected to be lower when Ceres is farther from the Sun in its orbit, and internally powered emissions should not be affected by its orbital position. The limited data previously available suggested cometary-style sublimation, but evidence from Dawn suggests geologic activity could be at least partially responsible.[98]

Studies using Dawn's gamma ray and neutron detector (GRaND) reveal that Ceres accelerates electrons from the solar wind; the most accepted hypothesis is that these electrons are being accelerated by collisions between the solar wind and a tenuous water vapour exosphere.[99] [100] Bow shocks like these could also be explained by a transient magnetic field, but this is considered less likely, as the interior of Ceres is not thought to be sufficiently electrically conductive. Ceres' thin exosphere is continuously replenished through exposure of water ice patches by impacts, water ice diffusion through the porous ice crust and proton sputtering during solar activity.[101] [102] [103] The rate of this vapour diffusion scales with grain size[104] and is heavily affected by a global dust mantle consisting of an aggregate of approximately 1 micron particles.[105] Exospheric replenishment through sublimation alone is very small, with the current outgassing rate being only 0.003 kg/s.[106] Various models of an extant exosphere have been attempted including ballistic trajectory, DSMC, and polar cap numerical models.[107] [108] [109] Results showed a water exosphere half-life of 7 hours from the ballistic trajectory model, an outgassing rate of 6 kg/s with an optically thin atmosphere sustained for tens of days using a DSMC model, and seasonal polar caps formed from exosphere water delivery using the polar cap model. The mobility of water molecules within the exosphere is dominated by ballistic hops coupled with interaction of the surface, however less is known about direct interactions with planetary regoliths.[106]

Origin and evolution

Ceres is a surviving protoplanet that formed 4.56billion years ago; alongside Pallas and Vesta, one of only three remaining in the inner Solar System,[110] with the rest either merging to form terrestrial planets, being shattered in collisions[111] or being ejected by Jupiter.[112] Despite Ceres's current location, its composition is not consistent with having formed within the asteroid belt. It seems rather that it formed between the orbits of Jupiter and Saturn, and was deflected into the asteroid belt as Jupiter migrated outward. The discovery of ammonium salts in Occator Crater supports an origin in the outer Solar System, as ammonia is far more abundant in that region.[113]

The early geological evolution of Ceres was dependent on the heat sources available during and after its formation: impact energy from planetesimal accretion and decay of radionuclides (possibly including short-lived extinct radionuclides such as aluminium-26). These may have been sufficient to allow Ceres to differentiate into a rocky core and icy mantle, or even a liquid water ocean, soon after its formation. This ocean should have left an icy layer under the surface as it froze. The fact that Dawn found no evidence of such a layer suggests that Ceres's original crust was at least partially destroyed by later impacts thoroughly mixing the ice with the salts and silicate-rich material of the ancient seafloor and the material beneath.

Ceres possesses surprisingly few large craters, suggesting that viscous relaxation and cryovolcanism have erased older geological features.[114] The presence of clays and carbonates requires chemical reactions at temperatures above 50°C, consistent with hydrothermal activity.[115]

It has become considerably less geologically active over time, with a surface dominated by impact craters; nevertheless, evidence from Dawn reveals that internal processes have continued to sculpt Ceres's surface to a significant extent[116] contrary to predictions that Ceres's small size would have ceased internal geological activity early in its history.[117]

Habitability

Although Ceres is not as actively discussed as a potential home for microbial extraterrestrial life as Mars, Europa, Enceladus, or Titan are, it has the most water of any body in the inner Solar System after Earth, and the likely brine pockets under its surface could provide habitats for life. Unlike Europa or Enceladus, it does not experience tidal heating, but it is close enough to the Sun, and contains enough long-lived radioactive isotopes, to preserve liquid water in its subsurface for extended periods. The remote detection of organic compounds and the presence of water mixed with 20% carbon by mass in its near surface could provide conditions favourable to organic chemistry. Of the biochemical elements, Ceres is rich in carbon, hydrogen, oxygen and nitrogen,[118] but phosphorus has yet to be detected,[119] and sulfur, despite being suggested by Hubble UV observations, was not detected by Dawn.

Observation and exploration

Observation

When in opposition near its perihelion, Ceres can reach an apparent magnitude of +6.7.[120] This is too dim to be visible to the average naked eye, but under ideal viewing conditions, keen eyes may be able to see it. Vesta is the only other asteroid that can regularly reach a similarly bright magnitude, while Pallas and 7 Iris do so only when both in opposition and near perihelion.[121] When in conjunction, Ceres has a magnitude of around +9.3, which corresponds to the faintest objects visible with 10×50 binoculars; thus, it can be seen with such binoculars in a naturally dark and clear night sky around new moon.

An occultation of the star BD+8°471 by Ceres was observed on 13 November 1984 in Mexico, Florida and across the Caribbean, allowing better measurements of its size, shape and albedo.[122] On 25 June 1995, Hubble obtained ultraviolet images of Ceres with 50-1NaN-1 resolution.[123] In 2002, the Keck Observatory obtained infrared images with 30-1NaN-1 resolution using adaptive optics.[124]

Before the Dawn mission, only a few surface features had been unambiguously detected on Ceres. High-resolution ultraviolet Hubble images in 1995 showed a dark spot on its surface, which was nicknamed "Piazzi" in honour of the discoverer of Ceres. It was thought to be a crater. Visible-light images of a full rotation taken by Hubble in 2003 and 2004 showed eleven recognisable surface features, the natures of which were undetermined.[125] [126] One of them corresponded to the Piazzi feature. Near-infrared images over a whole rotation, taken with adaptive optics by the Keck Observatory in 2012, showed bright and dark features moving with Ceres's rotation. Two dark features were circular and were presumed to be craters; one was observed to have a bright central region, and the other was identified as the Piazzi feature.[127] Dawn eventually revealed Piazzi to be a dark region in the middle of Vendimia Planitia, close to the crater Dantu, and the other dark feature to be within Hanami Planitia and close to Occator Crater.[128]

Dawn mission

See main article: Dawn (spacecraft). 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 proposed a high-priority mission to explore the asteroid belt using a spacecraft with an ion engine. Funding remained problematic for nearly a decade, but by 2004, the Dawn vehicle passed its critical design review.[129]

Dawn, the first space mission to visit either Vesta or Ceres, was launched on 27 September 2007. On 3 May 2011, Dawn acquired its first targeting image 1200000km (700,000miles) from Vesta.[130] After orbiting Vesta for thirteen months, Dawn used its ion engine to depart for Ceres, with gravitational capture occurring on 6 March 2015[131] at a separation of 61000km (38,000miles),[132] four months before the New Horizons flyby of Pluto.

The spacecraft instrumentation included a framing camera, a visual and infrared spectrometer, and a gamma-ray and neutron detector. These instruments examined Ceres's shape and elemental composition.[133] On 13 January 2015, as Dawn approached Ceres, the spacecraft took its first images at near-Hubble resolution, revealing impact craters and a small high-albedo spot on the surface. Additional imaging sessions, at increasingly better resolution, took place from February to April.[134]

Dawns mission profile called 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 13500km (8,400miles) on 23 April 2015, staying for only one orbit (15 days).[135] [136] The spacecraft then reduced its orbital distance to 4400km (2,700miles) for its second observational orbit ("survey") for three weeks,[137] then down to 1470km (910miles) ("HAMO;" high altitude mapping orbit) for two months[138] and then down to its final orbit at 375km (233miles) ("LAMO;" low altitude mapping orbit) for at least three months.[139] In October 2015, NASA released a true-colour portrait of Ceres made by Dawn.[140] In 2017, Dawns mission was extended to perform a series of closer orbits around Ceres until the hydrazine used to maintain its orbit ran out.[141]

Dawn soon discovered evidence of cryovolcanism. Two distinct bright spots (or high-albedo features) inside a crater (different from the bright spots observed in earlier Hubble images)[142] were seen in a 19 February 2015 image, leading to speculation about a possible cryovolcanic origin[143] or outgassing.[144] On 2 September 2016, scientists from the Dawn team argued in a Science paper that Ahuna Mons was the strongest evidence yet for cryovolcanic features on Ceres. On 11 May 2015, NASA released a higher-resolution image showing that the spots were composed of multiple smaller spots.[145] 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 hexahydrate (MgSO4·6H2O); the spots were also found to be associated with ammonia-rich clays.[146] In June 2016, near-infrared spectra of these bright areas were found to be consistent with a large amount of sodium carbonate, implying that recent geologic activity was probably involved in the creation of the bright spots.[147]

From June to October 2018, Dawn orbited Ceres from as close as to as far away as .[148] The Dawn mission ended on 1 November 2018 after the spacecraft ran out of fuel.[149]

Future missions

In 2020, an ESA team proposed the Calathus Mission concept, a followup mission to Occator Crater, to return a sample of the bright carbonate faculae and dark organics to Earth.[150] The Chinese Space Agency is designing a sample-return mission from Ceres that would take place during the 2020s.[151]

See also

External links

Notes and References

  1. Book: Schmadel, Lutz . Dictionary of minor planet names . Springer . 2003 . 978-3-540-00238-3 . 5th . Germany . 15 . Lutz D. Schmadel . 21 January 2021 . https://web.archive.org/web/20210216235253/https://books.google.com/books?id=KWrB1jPCa8AC&pg=PA15 . 16 February 2021 . live.
  2. Web site: AstDyS-2 Ceres Synthetic Proper Orbital Elements . live . https://web.archive.org/web/20111121225850/http://hamilton.dm.unipi.it/astdys/index.php?pc=1.1.6&n=1 . 21 November 2011 . 1 October 2011 . Department of Mathematics, University of Pisa, Italy.
  3. Ermakov . A. I. . Fu . R. R. . Castillo-Rogez . J. C. . Raymond . C. A. . Park . R. S. . Preusker . F. . Russell . C. T. . Smith . D. E. . Zuber . M. T. . Constraints on Ceres' Internal Structure and Evolution From Its Shape and Gravity Measured by the Dawn Spacecraft . Journal of Geophysical Research: Planets . November 2017 . 122 . 11 . 2267–2293 . 10.1002/2017JE005302. 2017JGRE..122.2267E . 133739176 . free .
  4. Park . R.S. . Vaughan . A.T. . Konopliv . A.S. . Ermakov . A.I. . Mastrodemos . N. . Castillo-Rogez . J.C. . Joy . S.P. . Nathues . A. . Polanskey . C.A. . Rayman . M.D. . Riedel . J.E. . Raymond . C.A. . Russell . C.T. . Zuber . M.T. . High-resolution shape model of Ceres from stereophotoclinometry using Dawn Imaging Data . Icarus . February 2019 . 319 . 812–827 . 10.1016/j.icarus.2018.10.024. 2019Icar..319..812P . 126268402 .
  5. Mao . X. . McKinnon . W. B. . 2018 . Faster paleospin and deep-seated uncompensated mass as possible explanations for Ceres' present-day shape and gravity . Icarus . 299 . 430–442 . 2018Icar..299..430M . 10.1016/j.icarus.2017.08.033.
  6. Konopliv . A.S. . Park . R.S. . Vaughan . A.T. . Bills . B.G. . Asmar . S.W. . Ermakov . A.I. . Rambaux . N. . Raymond . C.A. . Castillo-Rogez . J.C. . Russell . C.T. . Smith . D.E. . 2018 . The Ceres gravity field, spin pole, rotation period and orbit from the Dawn radiometric tracking and optical data . Icarus . 299 . 411–429 . 2018Icar..299..411K . 10.1016/j.icarus.2017.08.005 . Zuber . M.T..
  7. Web site: Asteroid Ceres P_constants (PcK) SPICE kernel file . live . https://web.archive.org/web/20200728153501/https://naif.jpl.nasa.gov/pub/naif/DAWN/kernels/pck/dawn_ceres_v06.tpc . 28 July 2020 . 8 September 2019 . NASA Navigation and Ancillary Information Facility.
  8. Surface temperature of dwarf planet Ceres: Preliminary results from Dawn . 46th Lunar and Planetary Science Conference . F.. Tosi. M. T.. Capria. etal. 2015. 11960 . 2015EGUGA..1711960T . 25 May 2021.
  9. Rivkin . A. S. . Volquardsen, E. L. . Clark, B. E. . 2006 . The surface composition of Ceres: Discovery of carbonates and iron-rich clays . live . Icarus . 185 . 2 . 563–567 . 2006Icar..185..563R . 10.1016/j.icarus.2006.08.022 . https://web.archive.org/web/20071128201130/http://irtfweb.ifa.hawaii.edu/~elv/icarus185.563.pdf . 28 November 2007 . 8 December 2007.
  10. Hogg . Helen Sawyer . 1948 . The Titius-Bode Law and the Discovery of Ceres . live . Journal of the Royal Astronomical Society of Canada . 242 . 241–246 . 1948JRASC..42..241S . https://web.archive.org/web/20210718191659/http://articles.adsabs.harvard.edu//full/1948JRASC..42..241S/0000244.000.html . 18 July 2021. 18 July 2021.
  11. Web site: Landau . Elizabeth . 26 January 2016 . Ceres: Keeping Well-Guarded Secrets for 215 Years . live . https://web.archive.org/web/20190524043553/https://www.jpl.nasa.gov/news/news.php?feature=4824 . 24 May 2019 . 26 January 2016 . NASA.
  12. Web site: Hoskin . Michael . 26 June 1992 . Bode's Law and the Discovery of Ceres . dead . https://web.archive.org/web/20071116022100/http://www.astropa.unipa.it/HISTORY/hoskin.html . 16 November 2007 . 5 July 2007 . Observatorio Astronomico di Palermo "Giuseppe S. Vaiana".
  13. Forbes . Eric G. . 1971 . Gauss and the Discovery of Ceres . live . Journal for the History of Astronomy . 2 . 3 . 195–199 . 1971JHA.....2..195F . 10.1177/002182867100200305 . https://web.archive.org/web/20210718200510/http://adsabs.harvard.edu/full/1971JHA.....2..195F . 18 July 2021 . 18 July 2021 . 125888612.
  14. Book: Cunningham, Clifford J. . The first asteroid: Ceres, 1801–2001 . Star Lab Press . 2001 . 978-0-9708162-1-4 . 23 October 2015 . https://web.archive.org/web/20160529144326/https://books.google.com/books?id=CXdMPwAACAAJ . 29 May 2016 . live.
  15. Book: Nieto, Michael Martin . The Titius-Bode Law of Planetary Distances: Its History and Theory . Pergamon Press . 1972 . 978-1-4831-5936-2 . 23 September 2021 . https://web.archive.org/web/20210929081229/https://books.google.co.uk/books?hl=en&lr=&id=NneoBQAAQBAJ&oi=fnd&pg=PP1&dq=bode+law+neptune+coincidence+1846&ots=LIplNAOXco&sig=qAF2y5xXTivecmSP_fjGCDA9Sx4&redir_esc=y . 29 September 2021 . live.
  16. Hughes . David W . 1994 . The Historical Unravelling of the Diameters of the First Four Asteroids . live . Quarterly Journal of the Royal Astronomical Society . 35 . 331–344 . 1994QJRAS..35..331H . https://web.archive.org/web/20210802115814/http://legacy.adsabs.harvard.edu/pdf/1994qjras..35..331h . 2 August 2021 . 2 August 2021.
  17. Book: Foderà Serio, G. . Asteroids III . Manara, A. . Sicoli, P. . University of Arizona Press . 2002 . W. F. Bottke Jr. . Tucson . 17–24 . Giuseppe Piazzi and the Discovery of Ceres . 25 June 2009 . A. Cellino . P. Paolicchi . R. P. Binzel . http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3027.pdf . https://web.archive.org/web/20120416221621/http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3027.pdf . 16 April 2012 . live.
  18. Book: Rüpke, Jörg . A Companion to Roman Religion . John Wiley and Sons . 2011 . 978-1-4443-4131-7 . 51–52 . Jörg Rüpke . 23 October 2015 . https://web.archive.org/web/20151115202651/https://books.google.com/books?id=FRRLOltuxDcC&pg=PT90 . 15 November 2015 . live.
  19. Web site: 21 September 2012 . Dawn Spacecraft Finds Traces of Water on Vesta . live . https://web.archive.org/web/20210923202702/https://scitechdaily.com/dawn-spacecraft-finds-traces-of-water-on-vesta/ . 23 September 2021 . 23 September 2021 . Sci-Tech Daily.
  20. Book: A. S. . Rivkin . etal . 2012 . The Surface Composition of Ceres . Christopher . Russell . Carol . Raymond . The Dawn Mission to Minor Planets 4 Vesta and 1 Ceres . 109 . Springer . 978-1-4614-4902-7.
  21. Book: Thornton . Word For Word From Horace . Nabu Press . 2012 . 978-1-279-56080-8 . 314 . Epode 16 . 1878.
  22. Book: Booth . Flowers of Roman Poesy . Harvard University . 1823.
  23. Web site: Cerium: historical information . live . https://web.archive.org/web/20100409042237/http://www.webelements.com/cerium/history.html . 9 April 2010 . 27 April 2007 . Adaptive Optics.
  24. Web site: JPL/NASA . 22 April 2015 . What is a Dwarf Planet? . 19 January 2022 . Jet Propulsion Laboratory . 8 December 2021 . https://web.archive.org/web/20211208181916/https://www.jpl.nasa.gov/infographics/what-is-a-dwarf-planet . live .
  25. Book: Cunningham, Clifford . 2015 . Discovery of the First Asteroid, Ceres . Springer Intl. . 69, 164, 206 . 978-3-319-21777-2 . 1100952738.
  26. Gould . B. A. . Benjamin Apthorp Gould . 1852 . On the symbolic notation of the asteroids . Astronomical Journal . 2 . 34 . 80 . 1852AJ......2...80G . 10.1086/100212.
  27. Web site: Hilton . James L. . 17 September 2001 . When Did the Asteroids Become Minor Planets? . dead . https://web.archive.org/web/20071106124911/http://aa.usno.navy.mil/faq/docs/minorplanets.php . 6 November 2007 . 16 August 2006 . US Naval Observatory.
  28. Herschel . William . William Herschel . 6 May 1802 . Observations on the two lately discovered celestial Bodies . Philosophical Transactions of the Royal Society of London . 92 . 213–232 . 1802RSPT...92..213H . 10.1098/rstl.1802.0010 . 107120 . 115664950.
  29. Metzger . Philip T. . Philip T. Metzger . Sykes . Mark V. . Stern . Alan . Runyon . Kirby . 2019 . The Reclassification of Asteroids from Planets to Non-Planets . Icarus . 319 . 21–32 . 10.1016/j.icarus.2018.08.026. 1805.04115 . 2019Icar..319...21M . 119206487 .
  30. News: Connor . Steve . 16 August 2006 . Solar system to welcome three new planets . The New Zealand Herald . live . 19 July 2021 . https://web.archive.org/web/20210719210858/https://www.nzherald.co.nz/technology/solar-system-to-welcome-three-new-planets/KQJAEQL22GMH4Y2ESZA7YIHBTM/ . 19 July 2021.
  31. Web site: Gingerich . Owen . Owen Gingerich . etal . 16 August 2006 . The IAU draft definition of "Planet" and "Plutons" . dead . https://web.archive.org/web/20080827210426/http://www.iau.org/iau0601.424.0.html . 27 August 2008 . 27 April 2007 . IAU.
  32. Web site: 16 August 2006 . The IAU Draft Definition of Planets And Plutons . live . https://web.archive.org/web/20090906072954/http://www.spacedaily.com/reports/The_IAU_Draft_Definition_Of_Planets_And_Plutons_999.html . 6 September 2009 . 27 April 2007 . SpaceDaily.
  33. Pitjeva . E. V. . Elena V. Pitjeva . Masses of the Main Asteroid Belt and the Kuiper Belt from the Motions of Planets and Spacecraft . Solar System Research . 44 . 8–9 . 554–566 . 2018 . 1811.05191 . 10.1134/S1063773718090050 . 2018AstL...44..554P . 119404378.
  34. Web site: In Depth | Ceres . live . https://web.archive.org/web/20190421175656/https://solarsystem.nasa.gov/planets/dwarf-planets/ceres/in-depth/ . 21 April 2019 . 21 April 2019 . NASA Solar System Exploration.
  35. Metzger . Philip T. . Philip T. Metzger . Grundy . W. M. . Mark V. . Sykes . Alan . Stern . James F. . Bell III . Charlene E. . Detelich . Kirby . Runyon . Michael . Summers . 2022 . Moons are planets: Scientific usefulness versus cultural teleology in the taxonomy of planetary science . Icarus . 374 . 114768 . 10.1016/j.icarus.2021.114768 . 2110.15285 . 2022Icar..37414768M . 240071005 . 8 August 2022.
  36. Web site: Science: One Mission, Two Remarkable Destinations . live . https://web.archive.org/web/20200717143754/https://solarsystem.nasa.gov/asteroids-comets-and-meteors/asteroids/overview/?page=0&per_page=40&order=name+asc&search=&condition_1=101:parent_id&condition_2=asteroid:body_type:ilike . 17 July 2020 . 14 July 2020 . NASA . Asteroids range in size from Vesta – the largest at about 329 miles (530 km) in diameter....
  37. Book: Lang, Kenneth . The Cambridge Guide to the Solar System . Cambridge University Press . 2011 . 978-1-139-49417-5 . 372, 442 . 27 July 2019 . https://web.archive.org/web/20200726125744/https://books.google.com/books?id=S4xDhVCxAQIC&pg=PR5 . 26 July 2020 . live.
  38. Web site: Question and answers 2 . live . https://web.archive.org/web/20160130022141/http://www.iau.org/public/themes/pluto/ . 30 January 2016 . 31 January 2008 . IAU . Ceres is (or now we can say it was) the largest asteroid... There are many other asteroids that can come close to the orbital path of Ceres..
  39. Web site: Spahr . T. B. . Timothy B. Spahr . 7 September 2006 . MPEC 2006-R19: Editorial Notice . live . https://web.archive.org/web/20081010120050/http://cfa-www.harvard.edu/mpec/K06/K06R19.html . 10 October 2008 . 31 January 2008 . Minor Planet Center . the numbering of "dwarf planets" does not preclude their having dual designations in possible separate catalogues of such bodies..
  40. Web site: IAU . USGS Astrogeology Science Center . NASA . Gazetteer of Planetary Nomenclature. Target: Ceres . live . https://web.archive.org/web/20171013231505/https://planetarynames.wr.usgs.gov/Page/CERES/target . 13 October 2017 . 27 September 2021.
  41. Book: Cellino, A. . Asteroids III . University of Arizona Press . 2002 . 633–643 (Table on p. 636) . Spectroscopic Properties of Asteroid Families . 2002aste.book..633C . etal . 6 August 2011 . http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3018.pdf . https://web.archive.org/web/20160328010330/http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3018.pdf . 28 March 2016 . live.
  42. 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 . 1996DPS....28.1009K.
  43. Christou . A. A. . 2000 . Co-orbital objects in the main asteroid belt . . 356 . L71–L74 . 2000A&A...356L..71C.
  44. Christou . A. A. . Wiegert . P. . January 2012 . A population of Main Belt Asteroids co-orbiting with Ceres and Vesta . Icarus . 217 . 1 . 27–42 . 1110.4810 . 2012Icar..217...27C . 10.1016/j.icarus.2011.10.016 . 0019-1035 . 59474402.
  45. Kovačević . A. B. . 2011 . Determination of the mass of Ceres based on the most gravitationally efficient close encounters . . 419 . 3 . 2725–2736 . 1109.6455 . 2012MNRAS.419.2725K . 10.1111/j.1365-2966.2011.19919.x. free .
  46. Web site: Rayman . Marc . 30 October 2015 . New Maps of Ceres Reveal Topography Surrounding Mysterious 'Bright Spots' . 13 September 2022 . NASA.
  47. Schorghofer . N. . Mazarico . E. . Platz . T. . Preusker . F. . Schröder . S. E. . Raymond . C. A. . Russell . C. T. . 6 July 2016 . The permanently shadowed regions of dwarf planet Ceres . Geophysical Research Letters . 43 . 13 . 6783–6789 . 2016GeoRL..43.6783S . 10.1002/2016GL069368 . free.
  48. Web site: Russell . C. T. . Raymond . C. A. . etal . 21 July 2015 . 05. Dawn Explores Ceres Results from the Survey Orbit . live . https://web.archive.org/web/20150905125337/http://nesf2015.arc.nasa.gov/sites/default/files/downloads/pdf/05.pdf . 5 September 2015 . 23 September 2021 . NASA.
  49. Web site: 2017 . Ice in Ceres' Shadowed Craters Linked to Tilt History . live . https://web.archive.org/web/20210515225206/https://solarsystem.nasa.gov/news/572/ice-in-ceres-shadowed-craters-linked-to-tilt-history/ . 15 May 2021 . 15 May 2021 . NASA Solar System Exploration.
  50. McCord . Thomas B. . Zambon . Francesca . 15 January 2019 . The surface composition of Ceres from the Dawn mission . live . Icarus . 318 . 2–13 . 2019Icar..318....2M . 10.1016/j.icarus.2018.03.004 . https://web.archive.org/web/20210520160515/https://www.sciencedirect.com/science/article/abs/pii/S0019103517303342 . 20 May 2021 . 25 July 2021 . 125115208.
  51. Web site: Rayman . Marc D. . 28 May 2015 . Dawn Journal, 28 May 2015 . dead . https://web.archive.org/web/20150530075157/http://dawnblog.jpl.nasa.gov/2015/05/28/dawn-journal-may-28-2015/ . 30 May 2015 . 29 May 2015 . Jet Propulsion Laboratory.
  52. Web site: Nola Taylor Redd . 23 May 2018 . Ceres: The Smallest and Closest Dwarf Planet . live . https://web.archive.org/web/20210905112623/https://www.space.com/22891-ceres-dwarf-planet.html . 5 September 2021 . 25 July 2021 . space.com.
  53. Book: Raymond . C. . European Planetary Science Congress . Castillo-Rogez . J. C. . Park . R. S. . Ermakov . A. . Bland . M. T. . Marchi . S. . Prettyman . T. . Ammannito . E. . De Sanctis . M. C. . September 2018 . 12 . Dawn Data Reveal Ceres' Complex Crustal Evolution . 4 . 19 July 2020 . https://meetingorganizer.copernicus.org/EPSC2018/EPSC2018-645-1.pdf . https://web.archive.org/web/20200130111631/https://meetingorganizer.copernicus.org/EPSC2018/EPSC2018-645-1.pdf . 30 January 2020 . live . Russell, C.T..
  54. Neumann . W. . Breuer . D. . Spohn . T. . 2 December 2015 . Modelling the internal structure of Ceres: Coupling of accretion with compaction by creep and implications for the water-rock differentiation . live . Astronomy & Astrophysics . 584 . A117 . 2015A&A...584A.117N . 10.1051/0004-6361/201527083 . https://web.archive.org/web/20160822053141/http://www.aanda.org/articles/aa/pdf/2015/12/aa27083-15.pdf . 22 August 2016 . 10 July 2016 . free.
  55. Bhatia . G.K. . Sahijpal . S. . 2017 . Thermal evolution of trans-Neptunian objects, icy satellites, and minor icy planets in the early solar system . Meteoritics & Planetary Science . 52 . 12 . 2470–2490 . 2017M&PS...52.2470B . 10.1111/maps.12952 . 133957919. free .
  56. Web site: The Solar Wind Interaction with Vesta and Ceres: Implications for their Magnetic Moments. Russell. C.T.. Villarreal. M.N.. Prettyman. T.H.. Yamashita. N.. ESA Cosmos. 16 May 2018. 10 October 2022.
  57. Nordheim . T.A. . Castillo-Rogez . J.C. . Villarreal . M.N. . Scully . J.E.C. . Costello . E.S. . 1 May 2022 . The Radiation Environment of Ceres and Implications for Surface Sampling . Astrobiology . en . 22 . 5 . 509–519 . 10.1089/ast.2021.0080 . 35447049 . 2022AsBio..22..509N . 248323790 . 1531-1074 . 22 July 2022 . 25 April 2022 . https://web.archive.org/web/20220425085338/https://www.liebertpub.com/doi/10.1089/ast.2021.0080 . live .
  58. Dawn mission's search for satellites of Ceres: Intact protoplanets don't have satellites. Icarus. 316. December 2018. 191–204. Lucy A.. McFadden . David R. . Skillman . N. . Memarsadeghi . 10.1016/j.icarus.2018.02.017. 2018Icar..316..191M . 125181684 .
  59. Web site: 3 September 2016 . Sulfur, Sulfur Dioxide, Graphitized Carbon Observed on Ceres . 8 September 2016 . spaceref.com . 29 September 2021 . https://web.archive.org/web/20210929081230/http://spaceref.com/ceres/sulfur-sulfur-dioxide-graphitized-carbon-observed-on-ceres.html . dead .
  60. New Constraints on the Abundance and Composition of Organic Matter on Ceres. Kaplan. Hannah H.. Milliken. Ralph E.. Alexander. Conel M. O’D.. Geophysical Research Letters. 45. 11. 5274–5282. 10.1029/2018GL077913. 21 May 2018. 2018GeoRL..45.5274K. 51801398. free.
  61. Marchi . S. . Raponi . A. . Prettyman . T. H. . De Sanctis . M. C. . Castillo-Rogez . J. . Raymond . C. A. . Ammannito . E. . Bowling . T. . Ciarniello . M. . Kaplan . H. . Palomba . E. . 2018 . An aqueously altered carbon-rich Ceres . . 3 . 2 . 140–145 . 10.1038/s41550-018-0656-0 . Russell . C. T. . Vinogradoff . V. . Yamashita . N. . 135013590.
  62. Marchi . S. . Ermakov . A. I. . Raymond . C. A. . Fu . R. R. . O'Brien . D. P. . Bland . M. T. . Ammannito . E. . De Sanctis . M. C. . Bowling . T. . Schenk . P. . Scully . J. E. C. . 26 July 2016 . The missing large impact craters on Ceres . . 7 . 12257 . 2016NatCo...712257M . 10.1038/ncomms12257 . 4963536 . 27459197 . Buczkowski . D. L. . Williams . D. A. . Hiesinger . H. . Russell . C. T..
  63. Nathues . A. . Platz . T. . Thangjam . G. . Hoffmann . M. . Scully . J.E.C. . Stein . N. . Ruesch . O. . Mengel . K. . 2019 . Occator crater in color at highest spatial resolution . Icarus . 320 . 24–38 . 10.1016/j.icarus.2017.12.021 . 2019Icar..320...24N . 0019-1035.
  64. Strom . R.G. . Marchi . S. . Malhotra . R. . 2018 . Ceres and the Terrestrial Planets Impact Cratering Record . Icarus . 302 . 104–108 . 1804.01229 . 2018Icar..302..104S . 10.1016/j.icarus.2017.11.013 . 119009942.
  65. Web site: 23 March 2018 . Hanami Planum on Ceres . live . https://web.archive.org/web/20210929081231/https://www.nasa.gov/image-feature/jpl/pia21921/hanami-planum-on-ceres/ . 29 September 2021 . 17 August 2021 . NASA.
  66. Schröder . Stefan E . Carsenty . Uri . Hauber . Ernst . Raymond . Carol . Russell . Christopher . May 2021 . The brittle boulders of dwarf planet Ceres . Planetary Science Journal . 2 . 3 . 111 . 2105.11841 . 2021PSJ.....2..111S . 10.3847/PSJ/abfe66 . 235187212 . free .
  67. Stern . Robert J. . Gerya . Taras . Tackley . Paul J. . January 2018 . Stagnant lid tectonics: Perspectives from silicate planets, dwarf planets, large moons, and large asteroids . Geoscience Frontiers . en . 9 . 1 . 103–119 . 10.1016/j.gsf.2017.06.004 . 2018GeoFr...9..103S . free . 20.500.11850/224778 . free .
  68. Buczkowski . D. . Scully . J. E. C. . Raymond . C. A. . Russell . C. T. . December 2017 . Exploring Tectonic Activity on Vesta and Ceres . live . American Geophysical Union, Fall Meeting 2017, Abstract #P53G-02 . 2017 . 2017AGUFM.P53G..02B . https://web.archive.org/web/20210929081257/https://ui.adsabs.harvard.edu/abs/2017AGUFM.P53G..02B/abstract . 29 September 2021 . 19 August 2021.
  69. Ruesch . O. . Platz . T. . Schenk . P. . McFadden . L. A. . Castillo-Rogez . J. C. . Quick . L. C. . Byrne . S. . Preusker . F. . OBrien . D. P. . Schmedemann . N. . Williams . D. A. . 2 September 2016 . Cryovolcanism on Ceres . Science . 353 . 6303 . aaf4286 . 2016Sci...353.4286R . 10.1126/science.aaf4286 . 27701087 . free . Li . J.- Y. . Bland . M. T. . Hiesinger . H. . Kneissl . T. . Neesemann . A. . Schaefer . M. . Pasckert . J. H. . Schmidt . B. E. . Buczkowski . D. L. . Sykes . M. V. . Nathues . A. . Roatsch . T. . Hoffmann . M. . Raymond . C. A. . Russell . C. T..
  70. Williams . David A. . Kneiss . T. . December 2018 . The geology of the Kerwan quadrangle of dwarf planet Ceres: Investigating Ceres' oldest, largest impact basin . live . Icarus . 316 . 99–113 . 2018Icar..316...99W . 10.1016/j.icarus.2017.08.015 . https://web.archive.org/web/20210816123323/https://www.sciencedirect.com/science/article/abs/pii/S0019103516305632?via%3Dihub . 16 August 2021 . 16 August 2021 . 85539501.
  71. Michael T. . Sori . Hanna G. . Sizemore . etal . December 2018 . Cryovolcanic rates on Ceres revealed by topography . Nature Astronomy . 2 . 12 . 946–950 . 2018NatAs...2..946S . 10.1038/s41550-018-0574-1 . 17 August 2021 . 186800298 .
  72. Sori . Michael M. . Byrne . Shane . Bland . Michael T. . Bramson . Ali M. . Ermakov . Anton I. . Hamilton . Christopher W. . Otto . Katharina A. . Ruesch . Ottaviano . Russell . Christopher T. . 2017 . The vanishing cryovolcanoes of Ceres . live . . 44 . 3 . 1243–1250 . 2017GeoRL..44.1243S . 10.1002/2016GL072319 . https://web.archive.org/web/20210929081236/https://repository.arizona.edu/bitstream/handle/10150/623032/Sori_et_al-2017-Geophysical_Research_Letters.pdf;jsessionid=36FE8987BD3FBEC127C6BCE092D3B831?sequence=1 . 29 September 2021 . 25 August 2019 . free . 10150/623032 . 52832191.
  73. Web site: 17 September 2018 . Ceres takes life an ice volcano at a time . live . https://web.archive.org/web/20201109040853/https://phys.org/news/2018-09-ceres-life-ice-volcano.html . 9 November 2020 . 22 April 2019 . University of Arizona . en-us.
  74. Web site: News – Ceres Spots Continue to Mystify in Latest Dawn Images . live . https://web.archive.org/web/20210725110508/https://solarsystem.nasa.gov/news/602/ceres-spots-continue-to-mystify-in-latest-dawn-images/ . 25 July 2021 . 25 July 2021 . NASA/JPL.
  75. Web site: USGS: Ceres nomenclature . live . https://web.archive.org/web/20151115202652/http://planetarynames.wr.usgs.gov/images/ceres.pdf . 15 November 2015 . 16 July 2015.
  76. Web site: Landau . Elizabeth . McCartney . Gretchen . 24 July 2018 . What Looks Like Ceres on Earth? . live . https://web.archive.org/web/20210531021809/https://www.nasa.gov/feature/jpl/what-looks-like-ceres-on-earth/ . 31 May 2021 . 26 July 2021 . NASA.
  77. Schenk . Paul . Sizemore . Hanna . etal . 1 March 2019 . The central pit and dome at Cerealia Facula bright deposit and floor deposits in Occator Crater, Ceres: Morphology, comparisons and formation . Icarus . 320 . 159–187 . 2019Icar..320..159S . 10.1016/j.icarus.2018.08.010 . 125527752.
  78. Web site: Rivkin . Andrew . 21 July 2015 . Dawn at Ceres: A haze in Occator Crater? . live . https://web.archive.org/web/20160514052923/http://www.planetary.org/blogs/guest-blogs/2015/0721-dawn-at-ceres-a-haze-in-occator-rivkin.html . 14 May 2016 . 8 March 2017 . The Planetary Society.
  79. Web site: Redd . Nola Taylor . Water Ice on Ceres Boosts Hopes for Buried Ocean [Video] ]. live . https://web.archive.org/web/20160407113800/http://www.scientificamerican.com/article/water-ice-on-ceres-boosts-hopes-for-buried-ocean-video/ . 7 April 2016 . 7 April 2016 . Scientific American.
  80. Vu . Tuan H. . Hodyss . Robert . Johnson . Paul V. . Choukroun . Mathieu . July 2017 . Preferential formation of sodium salts from frozen sodium-ammonium-chloride-carbonate brines – Implications for Ceres' bright spots . Planetary and Space Science . 141 . 73–77 . 2017P&SS..141...73V . 10.1016/j.pss.2017.04.014.
  81. McCord . Thomas B. . Zambon . Francesca . 2019 . The surface composition of Ceres from the Dawn mission . Icarus . 318 . 2–13 . 2019Icar..318....2M . 10.1016/j.icarus.2018.03.004 . 125115208.
  82. Quick . Lynnae C. . Buczkowski . Debra L. . Ruesch . Ottaviano . Scully . Jennifer E. C. . Castillo-Rogez . Julie . Raymond . Carol A. . Schenk . Paul M. . Sizemore . Hanna G. . Sykes . Mark V. . 1 March 2019 . A Possible Brine Reservoir Beneath Occator Crater: Thermal and Compositional Evolution and Formation of the Cerealia Dome and Vinalia Faculae . live . Icarus . 320 . 119–135 . 2019Icar..320..119Q . 10.1016/j.icarus.2018.07.016 . https://web.archive.org/web/20210929081233/https://www.sciencedirect.com/science/article/abs/pii/S0019103517306371 . 29 September 2021 . 9 June 2021 . 125508484.
  83. Stein . N. T. . Ehlmann . B. L. . 1 March 2019 . The formation and evolution of bright spots on Ceres . Icarus . 320 . 188–201 . 2019Icar..320..188S . 10.1016/j.icarus.2017.10.014 . free.
  84. News: McCartney . Gretchen . 11 August 2020 . Mystery solved: Bright areas on Ceres come from salty water below . . live . 12 August 2020 . https://web.archive.org/web/20200811150523/https://phys.org/news/2020-08-mystery-bright-areas-ceres-salty.html . 11 August 2020.
  85. Web site: Rogez . J. C. Castillo . Raymond . C. A. . Russell . C. T. . Team . Dawn . 2017 . Dawn at Ceres: What Have We Learned? . live . https://web.archive.org/web/20181008123813/http://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_183286.pdf . 8 October 2018 . 19 July 2021 . NASA, JPL.
  86. Michael T. . Bland . Carol A. . Raymond . etal . 2016 . Composition and structure of the shallow subsurface of Ceres revealed by crater morphology . live . Nature Geoscience . 9 . 7 . 538–542 . 2016NatGe...9..538B . 10.1038/ngeo2743 . https://web.archive.org/web/20210915144834/https://www.nature.com/articles/ngeo2743 . 15 September 2021 . 15 September 2021 . 10919/103024. free .
  87. Web site: Catalog Page for PIA22660 . live . https://web.archive.org/web/20190421180803/https://photojournal.jpl.nasa.gov/catalog/PIA22660 . 21 April 2019 . 21 April 2019 . photojournal.jpl.nasa.gov.
  88. Web site: 14 August 2018 . PIA22660: Ceres' Internal Structure (Artist's Concept) . live . https://web.archive.org/web/20190421180803/https://photojournal.jpl.nasa.gov/catalog/PIA22660 . 21 April 2019 . 22 April 2019 . Photojournal . Jet Propulsion Laboratory.
  89. Park . R. S. . Konopliv . A. S. . Bills . B. G. . Rambaux . N. . Castillo-Rogez . J. C. . Raymond . C. A. . Vaughan . A. T. . Ermakov . A. I. . Zuber . M. T. . Fu . R. R. . Toplis . M. J. . 3 August 2016 . A partially differentiated interior for (1) Ceres deduced from its gravity field and shape . Nature . 537 . 7621 . 515–517 . 2016Natur.537..515P . 10.1038/nature18955 . 27487219 . Russell . C. T. . Nathues . A. . Preusker . F. . 4459985.
  90. Neveu. M.. Desch. S. J.. 2016. Geochemistry, thermal evolution, and cryovolanism on Ceres with a muddy ice mantle. 47th Lunar and Planetary Science Conference. 42 . 23 . 10.1002/2015GL066375 . 51756619 . free.
  91. News: 6 April 2017 . Confirmed: Ceres Has a Transient Atmosphere . en . Universe Today . live . 14 April 2017 . https://web.archive.org/web/20170415103956/https://www.universetoday.com/134922/confirmed-ceres-transient-atmosphere/ . 15 April 2017.
  92. Küppers . M. . O'Rourke . L. . Bockelée-Morvan . D.. Dominique Bockelée-Morvan . Zakharov . V. . Lee . S. . Von Allmen . P. . Carry . B. . Teyssier . D. . Marston . A. . Müller . T. . Crovisier . J. . 23 January 2014 . Localized sources of water vapour on the dwarf planet (1) Ceres . Nature . 505 . 7484 . 525–527 . 2014Natur.505..525K . 10.1038/nature12918 . 0028-0836 . 24451541 . Barucci . M. A. . Moreno . R. . 4448395.
  93. Campins . H. . Comfort . C. M. . 23 January 2014 . Solar system: Evaporating asteroid . Nature . 505 . 7484 . 487–488 . 2014Natur.505..487C . 10.1038/505487a . 24451536 . free . 4396841.
  94. O'Brien . D. P. . Travis . B. J. . Feldman . W. C. . Sykes . M. V. . Schenk . P. M. . Marchi . S. . Russell . C. T. . Raymond . C. A. . March 2015 . The Potential for Volcanism on Ceres due to Crustal Thickening and Pressurisation of a Subsurface Ocean . 2831 . https://web.archive.org/web/20161105072942/http://www.hou.usra.edu/meetings/lpsc2015/pdf/2831.pdf . 5 November 2016 . 1 March 2015 . . live.
  95. Book: Jewitt . David . http://www2.ess.ucla.edu/~jewitt/papers/2015/JHA15.pdf . The Active Asteroids . Hsieh . Henry . Agarwal . Jessica . Asteroids IV . . 2015 . 978-0-8165-3213-1 . Michel . P. . 221–241 . 2015aste.book..221J . 10.2458/azu_uapress_9780816532131-ch012 . 30 January 2020 . others . 1 . https://web.archive.org/web/20210830232616/http://www2.ess.ucla.edu/~jewitt/papers/2015/JHA15.pdf . 30 August 2021 . live . 1502.02361 . 119209764.
  96. Book: Jewitt, D . Protostars and Planets V . Chizmadia, L. . Grimm, R. . Prialnik, D . University of Arizona Press . 2007 . 978-0-8165-2654-3 . Reipurth, B. . 863–878 . Water in the Small Bodies of the Solar System . 11 October 2012 . Jewitt, D. . Keil, K. . http://www.ifa.hawaii.edu/~meech/a740/2006/spring/papers/PPV2006.pdf . https://web.archive.org/web/20170810141735/http://www.ifa.hawaii.edu/~meech/a740/2006/spring/papers/PPV2006.pdf . 10 August 2017 . live.
  97. McCord . Thomas B. . Combe . Jean-Philippe . Castillo-Rogez . Julie C. . McSween . Harry Y. . Prettyman . Thomas H. . May 2022 . Ceres, a wet planet: The view after Dawn . Geochemistry . en . 82 . 2 . 125745 . 10.1016/j.chemer.2021.125745. 2022ChEG...82l5745M . free .
  98. 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. . 1 September 2016 . Cratering on Ceres: Implications for its crust and evolution . Science . 353 . 6303 . aaf4759 . 2016Sci...353.4759H . 10.1126/science.aaf4759 . 27701089 . free . 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..
  99. Web site: NASA/Jet Propulsion Laboratory . 1 September 2016 . Ceres' geological activity, ice revealed in new research . live . https://web.archive.org/web/20170405062528/https://www.sciencedaily.com/releases/2016/09/160901155103.htm . 5 April 2017 . 8 March 2017 . ScienceDaily.
  100. Russell . C. T. . Raymond . C. A. . Ammannito . E. . Buczkowski . D. L. . De Sanctis . M. C. . Hiesinger . H. . Jaumann . R. . Konopliv . A. S. . McSween . H. Y. . Nathues . A. . Park . R. S. . 2 September 2016 . Dawn arrives at Ceres: Exploration of a small, volatile-rich world . Science . en . 353 . 6303 . 1008–1010 . 10.1126/science.aaf4219 . 27701107 . 2016Sci...353.1008R . 33455833 . 0036-8075 . free .
  101. Schorghofer . Norbert . Byrne . Shane . Landis . Margaret E. . Mazarico . Erwan . Prettyman . Thomas H. . Schmidt . Britney E. . Villarreal . Michaela N. . Castillo-Rogez . Julie . Raymond . Carol A. . Russell . Christopher T. . 20 November 2017 . The Putative Cerean Exosphere . The Astrophysical Journal . 850 . 1 . 85 . 10.3847/1538-4357/aa932f . free . 2017ApJ...850...85S . 0004-637X. 10150/626261 . free .
  102. Schörghofer . Norbert . Benna . Mehdi . Berezhnoy . Alexey A. . Greenhagen . Benjamin . Jones . Brant M. . Li . Shuai . Orlando . Thomas M. . Prem . Parvathy . Tucker . Orenthal J. . Wöhler . Christian . September 2021 . Water Group Exospheres and Surface Interactions on the Moon, Mercury, and Ceres . Space Science Reviews . en . 217 . 6 . 74 . 10.1007/s11214-021-00846-3 . 2021SSRv..217...74S . 0038-6308. free .
  103. Küppers . Michael . O’Rourke . Laurence . Bockelée-Morvan . Dominique . Zakharov . Vladimir . Lee . Seungwon . von Allmen . Paul . Carry . Benoît . Teyssier . David . Marston . Anthony . Müller . Thomas . Crovisier . Jacques . Barucci . M. Antonietta . Moreno . Raphael . January 2014 . Localized sources of water vapour on the dwarf planet (1) Ceres . Nature . en . 505 . 7484 . 525–527 . 10.1038/nature12918 . 24451541 . 2014Natur.505..525K . 0028-0836.
  104. Prettyman . T. H. . Yamashita . N. . Toplis . M. J. . McSween . H. Y. . Schörghofer . N. . Marchi . S. . Feldman . W. C. . Castillo-Rogez . J. . Forni . O. . Lawrence . D. J. . Ammannito . E. . Ehlmann . B. L. . Sizemore . H. G. . Joy . S. P. . Polanskey . C. A. . 6 January 2017 . Extensive water ice within Ceres' aqueously altered regolith: Evidence from nuclear spectroscopy . Science . en . 355 . 6320 . 55–59 . 10.1126/science.aah6765 . 27980087 . 2017Sci...355...55P . 0036-8075.
  105. Rivkin . Andrew S. . Li . Jian-Yang . Milliken . Ralph E. . Lim . Lucy F. . Lovell . Amy J. . Schmidt . Britney E. . McFadden . Lucy A. . Cohen . Barbara A. . 1 December 2011 . The Surface Composition of Ceres . Space Science Reviews . en . 163 . 1 . 95–116 . 10.1007/s11214-010-9677-4 . 2011SSRv..163...95R . 1572-9672.
  106. Schörghofer . Norbert . Benna . Mehdi . Berezhnoy . Alexey A. . Greenhagen . Benjamin . Jones . Brant M. . Li . Shuai . Orlando . Thomas M. . Prem . Parvathy . Tucker . Orenthal J. . Wöhler . Christian . 1 September 2021 . Water Group Exospheres and Surface Interactions on the Moon, Mercury, and Ceres . Space Science Reviews . en . 217 . 6 . 74 . 10.1007/s11214-021-00846-3 . 2021SSRv..217...74S . 1572-9672. free .
  107. Tu . L. . Ip . W. -H. . Wang . Y. -C. . 1 December 2014 . A Sublimation-driven Exospheric Model of Ceres . Planetary and Space Science . 104 . 157–162 . 10.1016/j.pss.2014.09.002 . 2014P&SS..104..157T . 0032-0633.
  108. Küppers . Michael . O’Rourke . Laurence . Bockelée-Morvan . Dominique . Zakharov . Vladimir . Lee . Seungwon . von Allmen . Paul . Carry . Benoît . Teyssier . David . Marston . Anthony . Müller . Thomas . Crovisier . Jacques . Barucci . M. Antonietta . Moreno . Raphael . January 2014 . Localized sources of water vapour on the dwarf planet (1) Ceres . Nature . en . 505 . 7484 . 525–527 . 10.1038/nature12918 . 24451541 . 2014Natur.505..525K . 1476-4687.
  109. Hayne . P. O. . Aharonson . O. . September 2015 . Thermal stability of ice on Ceres with rough topography . Journal of Geophysical Research: Planets . en . 120 . 9 . 1567–1584 . 10.1002/2015JE004887 . 2015JGRE..120.1567H . 2169-9097.
  110. McCord . Thomas B. . McFadden . Lucy A. . Russell . Christopher T. . Sotin . Christophe . Thomas . Peter C. . 7 March 2006 . Ceres, Vesta, and Pallas: Protoplanets, Not Asteroids . Eos . 87 . 105 . 2006EOSTr..87..105M . 10.1029/2006EO100002 . 10 . 12 September 2021 . 28 September 2021 . https://web.archive.org/web/20210928160233/https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2006EO100002 . live .
  111. Yang . Jijin . Goldstein . Joseph I. . Scott . Edward R. D. . and . 2007 . Iron meteorite evidence for early formation and catastrophic disruption of protoplanets . live . Nature . 446 . 7138 . 888–891 . 2007Natur.446..888Y . 10.1038/nature05735 . 17443181 . 4335070 . https://web.archive.org/web/20210929081247/https://www.nature.com/articles/nature05735 . 29 September 2021 . 16 September 2021.
  112. Petit . Jean-Marc . Morbidelli, Alessandro . 2001 . The Primordial Excitation and Clearing of the Asteroid Belt . live . Icarus . 153 . 2 . 338–347 . 2001Icar..153..338P . 10.1006/icar.2001.6702 . https://web.archive.org/web/20070221085835/http://www.gps.caltech.edu/classes/ge133/reading/asteroids.pdf . 21 February 2007 . 25 June 2009.
  113. Web site: Greicius . Tony . 29 June 2016 . Recent Hydrothermal Activity May Explain Ceres' Brightest Area . live . https://web.archive.org/web/20190106142353/https://www.nasa.gov/feature/jpl/recent-hydrothermal-activity-may-explain-ceres-brightest-area . 6 January 2019 . 26 July 2016 . nasa.gov.
  114. Web site: Atkinson . Nancy . 26 July 2016 . Large Impact Craters on Ceres Have Gone Missing . live . https://web.archive.org/web/20210515221501/https://www.universetoday.com/130048/large-impact-craters-ceres-gone-missing/ . 15 May 2021 . 15 May 2021 . Universe Today.
  115. Castillo-Rogez . Julie C. . Neveu . Marc . 1 . 31 January 2020 . Ceres: Astrobiological Target and Possible Ocean World . Astrobiology . 20 . 269–291 . 2020AsBio..20..269C . 10.1089/ast.2018.1999 . 31904989 . free . 2.
  116. Web site: Wall . Mike . 2 September 2016 . NASA's Dawn Mission Spies Ice Volcanoes on Ceres . live . https://web.archive.org/web/20170603034829/https://www.scientificamerican.com/article/nasa-s-dawn-mission-spies-ice-volcanoes-on-ceres/ . 3 June 2017 . 8 March 2017 . Scientific American.
  117. Castillo-Rogez . J. C. . McCord, T. B. . Davis, A. G. . 2007 . Ceres: evolution and present state . live . Lunar and Planetary Science . XXXVIII . 2006–2007 . https://web.archive.org/web/20110224014228/http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2006.pdf . 24 February 2011 . 25 June 2009.
  118. Characteristics of organic matter on Ceres from VIR/Dawn high spatial resolution spectra. Monthly Notices of the Royal Astronomical Society. 482. 2. 2407–2421. 10.1093/mnras/sty2772. 17 October 2018. De Sanctis . M. C. . Vinogradoff . V. . Raponi . A. . Ammannito . E. . Ciarniello . M. . Carrozzo . F. G. . De Angelis . S. . Raymond . C. A. . Russell . C. T.. free.
  119. Web site: Specktor . Brandon . 19 January 2021 . Humans could move to this floating asteroid belt colony in the next 15 years, astrophysicist says . live . https://web.archive.org/web/20210624204427/https://www.livescience.com/megasatellite-colony-ceres-oneill-cylinder.html . 24 June 2021 . 23 June 2021 . Live Science .
  120. Book: Menzel, Donald H. . A Field Guide to the Stars and Planets . Pasachoff, Jay M. . . 1983 . 978-0-395-34835-2 . 2nd . Boston . 391 . registration.
  121. Book: Martinez, Patrick . The Observer's Guide to Astronomy . . 1994 . 298 . 978-0-521-37945-8 . 984418486.
  122. Millis . L. R. . Wasserman, L. H. . Franz, O. Z. . etal . 1987 . The size, shape, density, and albedo of Ceres from its occultation of BD+8°471 . Icarus . 72 . 3 . 507–518 . 1987Icar...72..507M . 10.1016/0019-1035(87)90048-0 . free . 2060/19860021993.
  123. Parker . J. W. . Stern, Alan S. . Thomas Peter C. . etal . 2002 . Analysis of the first disk-resolved images of Ceres from ultraviolet observations with the Hubble Space Telescope . The Astronomical Journal . 123 . 1 . 549–557 . astro-ph/0110258 . 2002AJ....123..549P . 10.1086/338093 . 119337148.
  124. Web site: 11 October 2006 . Keck Adaptive Optics Images the Dwarf Planet Ceres . dead . https://web.archive.org/web/20090818054459/http://www.adaptiveoptics.org/News_1006_2.html . 18 August 2009 . 27 April 2007 . Adaptive Optics.
  125. Li . Jian-Yang . McFadden, Lucy A. . Parker, Joel Wm. . 2006 . Photometric analysis of 1 Ceres and surface mapping from HST observations . Icarus . 182 . 1 . 143–160 . 2006Icar..182..143L . 10.1016/j.icarus.2005.12.012.
  126. News: 7 September 2005 . Largest Asteroid May Be 'Mini Planet' with Water Ice . HubbleSite . live . 20 July 2021 . https://web.archive.org/web/20210720151550/https://hubblesite.org/contents/news-releases/2005/news-2005-27.html . 20 July 2021.
  127. Carry . Benoit . etal . 2007 . Near-Infrared Mapping and Physical Properties of the Dwarf-Planet Ceres . dead . Astronomy & Astrophysics . 478 . 1 . 235–244 . 0711.1152 . 2008A&A...478..235C . 10.1051/0004-6361:20078166 . https://web.archive.org/web/20080530130946/http://www2.keck.hawaii.edu/inst/people/conrad/nsfGrantRef/2007-arXiv-Benoit.Carry.pdf . 30 May 2008 . 6723533.
  128. Houtkooper . J. M. . Schulze-Makuch . D. . 2017 . Ceres: A Frontier in Astrobiology . live . Astrobiology Science Conference . https://web.archive.org/web/20210830232441/https://www.hou.usra.edu/meetings/abscicon2017/pdf/3252.pdf . 30 August 2021 . 19 August 2021 . 1965.
  129. Russell . C. T. . Capaccioni, F. . Coradini, A. . etal . October 2007 . Dawn Mission to Vesta and Ceres . live . Earth, Moon, and Planets . 101 . 1–2 . 65–91 . 2007EM&P..101...65R . 10.1007/s11038-007-9151-9 . https://web.archive.org/web/20201025132219/http://www-ssc.igpp.ucla.edu/personnel/russell/papers/dawn_mission_vesta_ceres.pdf . 25 October 2020 . 13 June 2011 . 46423305.
  130. Web site: Cook, Jia-Rui C. . Brown, Dwayne C. . 11 May 2011 . NASA's Dawn Captures First Image of Nearing Asteroid . live . https://web.archive.org/web/20110514045000/http://www.nasa.gov/mission_pages/dawn/news/dawn20110511.html . 14 May 2011 . 14 May 2011 . NASA/JPL.
  131. Web site: Schenk . P. . 15 January 2015 . Year of the 'Dwarves': Ceres and Pluto Get Their Due . live . https://web.archive.org/web/20150221192427/http://www.planetary.org/blogs/guest-blogs/2015/0115-year-of-the-dwarves-ceres-and-pluto.html . 21 February 2015 . 10 February 2015 . Planetary Society.
  132. Web site: Rayman . Marc . 1 December 2014 . Dawn Journal: Looking Ahead at Ceres . live . https://web.archive.org/web/20150226155456/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20141201-dawn-journal-looking-ahead-at-ceres.html . 26 February 2015 . 2 March 2015 . Planetary Society.
  133. Russel . C. T. . Capaccioni, F. . Coradini, A. . etal . 2006 . Dawn Discovery mission to Vesta and Ceres: Present status . Advances in Space Research . 38 . 9 . 2043–2048 . 1509.05683 . 2006AdSpR..38.2043R . 10.1016/j.asr.2004.12.041.
  134. Web site: Rayman . Marc . 30 January 2015 . Dawn Journal: Closing in on Ceres . live . https://web.archive.org/web/20150301124801/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20150130-dawn-journal-closing-in-on-ceres.html . 1 March 2015 . 2 March 2015 . Planetary Society.
  135. Web site: Rayman . Marc . 6 March 2015 . Dawn Journal: Ceres Orbit Insertion! . live . https://web.archive.org/web/20150308124208/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20150306-dawn-journal-ceres-orbit-insertion.html . 8 March 2015 . 6 March 2015 . The Planetary Society.
  136. Web site: Rayman . Marc . 3 March 2014 . Dawn Journal: Maneuvering Around Ceres . live . https://web.archive.org/web/20150226153757/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20140303-dawn-journal-maneuvering-around-ceres.html . 26 February 2015 . 6 March 2015 . Planetary Society.
  137. Web site: Rayman . Marc . 30 April 2014 . Dawn Journal: Explaining Orbit Insertion . live . https://web.archive.org/web/20150226162736/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20140430-dawn-journal-explaining-orbit-insertion.html . 26 February 2015 . 6 March 2015 . Planetary Society.
  138. Web site: Rayman . Marc . 30 June 2014 . Dawn Journal: HAMO at Ceres . live . https://web.archive.org/web/20150226161929/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20140701-dawn-journal-hamo-at-ceres.html . 26 February 2015 . 6 March 2015 . Planetary Society.
  139. Web site: Rayman . Marc . 31 August 2014 . Dawn Journal: From HAMO to LAMO and Beyond . live . https://web.archive.org/web/20150301124736/http://www.planetary.org/blogs/guest-blogs/marc-rayman/20140902-dawn-journal-from-hamo-to-lamo.html . 1 March 2015 . 6 March 2015 . Planetary Society.
  140. Web site: Dawn data from Ceres publicly released: Finally, color global portraits! . live . https://web.archive.org/web/20151109123619/http://www.planetary.org/blogs/emily-lakdawalla/2015/10221314-dawn-data-from-ceres-publicly.html . 9 November 2015 . 9 November 2015 . The Planetary Society.
  141. Web site: 19 October 2017 . Dawn Mission Extended at Ceres . 1 October 2021 . NASA/JPL-Caltech . 1 October 2021 . https://web.archive.org/web/20211001203348/https://www.jpl.nasa.gov/news/dawn-mission-extended-at-ceres . live .
  142. Plait . Phil . Phil Plait . 11 May 2015 . The Bright Spots of Ceres Spin Into View . live . . https://web.archive.org/web/20150529062723/http://www.slate.com/blogs/bad_astronomy/2015/05/11/ceres_new_images_show_many_many_bright_spots.html . 29 May 2015 . 30 May 2015.
  143. Web site: O'Neill . Ian . 25 February 2015 . Ceres' Mystery Bright Dots May Have Volcanic Origin . live . https://web.archive.org/web/20160814104158/http://www.seeker.com/ceres-mystery-bright-dots-may-have-volcanic-origin-1769548974.html . 14 August 2016 . 1 March 2015 . Discovery Inc..
  144. Web site: Lakdawalla . Emily . Emily Lakdawalla . 2015 . LPSC 2015: First results from Dawn at Ceres: provisional place names and possible plumes . live . https://web.archive.org/web/20160506035930/http://www.planetary.org/blogs/emily-lakdawalla/2015/03191629-lpsc-2015-dawn-at-ceres.html . 6 May 2016 . 23 September 2021 . The Planetary Society.
  145. Web site: 11 May 2015 . Ceres RC3 Animation . live . https://web.archive.org/web/20210117042828/https://www.jpl.nasa.gov/images/ceres-rc3-animation/ . 17 January 2021 . 31 July 2015 . Jet Propulsion Laboratory.
  146. Web site: Landau . Elizabeth . 9 December 2015 . New Clues to Ceres' Bright Spots and Origins . live . https://web.archive.org/web/20151209215813/http://phys.org/news/2015-12-clues-ceres-bright.html . 9 December 2015 . 10 December 2015 . phys.org.
  147. De Sanctis . M. C. . et al . 29 June 2016 . Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres . . 536 . 7614 . 54–57 . 2016Natur.536...54D . 10.1038/nature18290 . 27362221 . 4465999.
  148. Web site: Rayman . Marc . 13 June 2018 . Dawn – Mission Status . live . https://web.archive.org/web/20180623200554/https://dawn.jpl.nasa.gov/mission/status_2018.html . 23 June 2018 . 16 June 2018 . Jet Propulsion Laboratory.
  149. Web site: Rayman . Marc . 2018 . Dear Dawntasmagorias . live . https://web.archive.org/web/20210721141849/https://www.jpl.nasa.gov/blog/2018/11/dear-dawntasmagorias . 21 July 2021 . 21 July 2021 . NASA Jet Propulsion Laboratory.
  150. Kissick, L. E. . Acciarini, G. . Bates, H. . etal . 2020 . Sample Return From A Relic Ocean World: The Calthus Mission To Occator Crater, Ceres . live . 51st Lunar and Planetary Science Conference . https://web.archive.org/web/20201026101337/https://www.hou.usra.edu/meetings/lpsc2020/pdf/1291.pdf . 26 October 2020 . 1 February 2020.
  151. Web site: Zou, Yongliao . Li, Wei . Ouyang Ziyuan . China's Deep-space Exploration to 2030 . live . https://web.archive.org/web/20141214210927/http://english.nssc.cas.cn/ns/NU/201410/W020141016603613379886.pdf . 14 December 2014 . 23 September 2021 . Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Ceres (dwarf planet)".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.