which of jupiter's moons has an ice surface
Jupiter's moons in fiction


also been known for its abundant volcanism. Europa is the smallest of the four Galilean satellites and the second closest to Jupiter. It is theorized to have an ocean of liquid water underneath its icy surface; the thickness of the ice is much debated. The probable presence of the water ocean has made it a favored location for modern fictional speculation about extraterrestrial life in the Solar System. Ganymede is the third of the Galilean moons from Jupiter. It is the largest moon in the Solar System, bigger than the planet Mercury (
22157277
Galilean moons


decreases with distance from Jupiter. Callisto, the outermost and least dense of the four, has a density intermediate between ice and rock whereas Io, the innermost and densest moon, has a density intermediate between rock and iron. Callisto has an ancient, heavily cratered and unaltered ice surface and the way it rotates indicates that its density is equally distributed, suggesting that it has no rocky or metallic core but consists of a homogeneous mix of rock and ice. This may well have been the original structure of all the moons.
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Metis (moon)


ice with a porosity of 10–15%. The surface of Metis is heavily cratered, dark, and appears to be reddish in color. There is a substantial asymmetry between leading and trailing hemispheres: the leading hemisphere is 1.3 times brighter than the trailing one. The asymmetry is probably caused by the higher velocity and frequency of impacts on the leading hemisphere, which excavate a bright material (presumably ice) from its interior. Metis is the innermost of Jupiter's four small inner moons. It orbits Jupiter at a distance of ~128,000
1071009
Amorphous ice


Jupiter. Closer to Jupiter than the other three moons, Europa receives the highest level of radiation and thus through irradiation has the most amorphous ice. Callisto is the farthest from Jupiter, receiving the lowest radiation flux and therefore maintaining its crystalline ice. Ganymede, which lies between the two, exhibits amorphous ice at high latitudes and crystalline ice at the lower latitudes. This is thought to be the result of the moon's intrinsic magnetic field, which would funnel the charged particles to higher latitudes and protect the lower latitudes from irradiation
1705022
Planetary engineering


process of deliberately modifying the atmosphere, temperature, or environment of a planet, moon, or other body to be similar to those of Earth in order to make it habitable by humans. Seeding is a term used for the process of introducing microbial or algae species on a planet or moon already offering habitable regions. Jupiter's moon Europa is a good example as it has a well protected ocean under a thick ice crust. Living on the surface of the ice crust is not possible, but some microorganisms from Earth could possibly
19825439
Moons of Jupiter


J 23. A number of other moons have only been observed for a year or two, but have decent enough orbits to be easily measurable even in 2018. The first spacecraft to visit Jupiter were "Pioneer 10" in 1973, and "Pioneer 11" a year later, taking low-resolution images of the four Galilean moons. The "Voyager 1" and "Voyager 2" probes visited Jupiter in 1979, discovering the volcanic activity on Io and the presence of water ice on the surface of Europa. The
13336326
Jupiter Icy Moons Explorer


and minor gas species on Jupiter and will investigate the composition of ices and minerals on the surfaces of the icy moons. The spatial resolution will be down to 75 m (246.1 ft) on Ganymede and about 100 km (62.1 mi) on Jupiter. UV imaging Spectrograph ("UVS") is an imaging spectrograph operating in the wavelength range 55–210 nm with spectral resolution of that will characterise exospheres and aurorae of the icy moons, including plume searches on Europa, and study the Jovian upper atmosphere and aurorae. It will
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Callisto (moon)


of rock and ices, with a density of about , the lowest density and surface gravity of Jupiter's major moons. Compounds detected spectroscopically on the surface include water ice, carbon dioxide, silicates, and organic compounds. Investigation by the "Galileo" spacecraft revealed that Callisto may have a small silicate core and possibly a subsurface ocean of liquid water at depths greater than . The surface of Callisto is the oldest and most heavily cratered in the Solar System. Its surface is completely covered with impact craters. It does not show
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Galilean moons


is to Jupiter the hotter its interior. The current model is that the moons experience tidal heating as a result of the gravitational field of Jupiter in inverse proportion to the square of their distance from the giant planet. In all but Callisto this will have melted the interior ice, allowing rock and iron to sink to the interior and water to cover the surface. In Ganymede a thick and solid ice crust then formed. In warmer Europa a thinner more easily broken crust formed. In Io the heating is so extreme that all
12146115
Marine life


. Europa, one of the moons orbiting Jupiter, is slightly smaller than the Earth's moon. There is a strong possibility a large saltwater ocean exists beneath its ice surface. It has been estimated the outer crust of solid ice is about 10–30 km (6–19 mi) thick and the liquid ocean underneath is about 100 km (60 mi) deep. This would make Europa's ocean over twice the volume of the Earth's ocean. There has been speculation Europa's ocean could support life, and could be capable of
2724406
Amalthea (moon)


color is currently unknown. The surface of Amalthea is slightly brighter than surfaces of other inner satellites of Jupiter. There is also a substantial asymmetry between leading and trailing hemispheres: the leading hemisphere is 1.3 times brighter than the trailing one. The asymmetry is probably caused by the higher velocity and frequency of impacts on the leading hemisphere, which excavate a bright material—presumably ice—from the interior of the moon. Amalthea is irregularly shaped, with the best ellipsoidal approximation being . From this, Amalthea's surface area is likely
3192640
Extraterrestrial (TV program)


a Jupiter-like planet that is cool enough to have visible rain clouds in its atmosphere) orbiting a close binary star system. The Blue Moon itself is roughly an earth mass but has an air pressure around three times that of Earth's at sea level. A distinguishing feature of Blue Moon is that it has no polar ice caps: the thick atmosphere keeps temperatures constant across the moon's surface. There is also a greenish haze over the moon from large carpets of floating moss and algae. The denser atmosphere allows more
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Water


: Liquid water is present on Earth, covering 71% of its surface. Liquid water is also occasionally present in small amounts on Mars. Scientists believe liquid water is present in the Saturnian moons of Enceladus, as a 10-kilometre thick ocean approximately 30–40 kilometres below Enceladus' south polar surface, and Titan, as a subsurface layer, possibly mixed with ammonia. Jupiter's moon Europa has surface characteristics which suggest a subsurface liquid water ocean. Liquid water may also exist on Jupiter's moon Ganymede as a layer sandwiched between high pressure
14723418
Extraterrestrial life


, and Callisto. The EJSM/Laplace mission is planned to determine the habitability of these environments. Jupiter's moon Europa has been subject to speculation about the existence of life due to the strong possibility of a liquid water ocean beneath its ice surface. Hydrothermal vents on the bottom of the ocean, if they exist, may warm the water and could be capable of supporting nutrients and energy to microorganisms. It is also possible that Europa could support aerobic macrofauna using oxygen created by cosmic rays impacting its surface ice. The case
9556094
Adrastea (moon)


daughter of Zeus and his lover Ananke. Although the "Juno" orbiter, which arrived at Jupiter in 2016, has a camera called JunoCam, it is almost entirely focused on observations of Jupiter itself. However, if all goes well should be able to capture some limited images of the Jupiter moons Metis and Adrastea. Adrastea has an irregular shape and measures 20×16×14 km across. A surface area estimate would be between 840 and 1,600 (~1,200) km. This makes it the smallest of the four inner moons. The bulk
2387130
Crater counting


returned from the Moon by the Luna and Apollo missions. It has been used to estimate the age of areas on Mars and other planets that were covered by lava flows, on the Moon of areas covered by giant mares, and how long ago areas on the icy moons of Jupiter and Saturn flooded with new ice. What one needs to count using the crater counting method are "independent" craters. However, not all craters on a given surface are independent: Secondary craters ('secondaries') are craters formed by
19020847
Titan (moon)


by the Dutch astronomer Christiaan Huygens, Titan was the first known moon of Saturn, and the sixth known planetary satellite (after Earth's moon and the four Galilean moons of Jupiter). Titan orbits Saturn at 20 Saturn radii. From Titan's surface, Saturn subtends an arc of 5.09 degrees and would appear 11.4 times larger in the sky than the Moon from Earth. Titan is primarily composed of ice and rocky material. Much as with Venus before the Space Age, the dense opaque atmosphere prevented understanding of Titan's surface
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Exosphere


little is known about it due to lack of research. Mercury, the Moon and the Galilean satellites of Jupiter have surface boundary exospheres, which are exospheres without a denser atmosphere underneath. Mercury and several large moons, such as the Moon and the Galilean satellites of Jupiter, have exospheres without a denser atmosphere underneath, referred to as a surface boundary exosphere. Here, molecules are ejected on elliptic trajectories until they collide with the surface. Smaller bodies such as asteroids, in which the molecules emitted from the surface escape to space
1856409
Extraterrestrial liquid water


a moon of Jupiter, following observation by the Hubble Space Telescope in 2015. Patterns in auroral belts and rocking of the magnetic field suggest the presence of an ocean. It is estimated to be 100 km deep with the surface lying below a crust of 150 km of ice. Ceres appears to be differentiated into a rocky core and 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
21093302
Space colonization


The target chosen was Callisto due to its distance from Jupiter, and thus the planet's harmful radiation. It could be possible to build a surface base that would produce fuel for further exploration of the Solar System. Three of the Galilean moons (Europa, Ganymede, Callisto) have an abundance of volatiles that may support colonization efforts. Titan is suggested as a target for colonization, because it is the only moon in the Solar System to have a dense atmosphere and is rich in carbon-bearing compounds. Titan has ice
9946399
Amalthea (moon)


Amalthea ( ; ) is the third moon of Jupiter in order of distance from the planet. It was discovered on 9 September 1892, by Edward Emerson Barnard and named after Amalthea, a nymph in Greek mythology. It is also known as . Amalthea is in a close orbit around Jupiter and is within the outer edge of the Amalthea Gossamer Ring, which is formed from dust ejected from its surface. From its surface, Jupiter would appear 46.5 degrees in diameter. Amalthea is the largest of the inner satellites of Jupiter.
3192635
Moons of Jupiter


from asteroids captured by Jupiter's gravitational field. These families bear the names of their largest members. The identification of satellite families is tentative, but the following are typically listed: The moons of Jupiter are listed below by orbital period. Moons massive enough for their surfaces to have collapsed into a spheroid are highlighted in bold. These are the four Galilean moons, which are comparable in size to the Moon. The other moons are much smaller, with the least massive Galilean moon being more than 7000 times more massive than the
13336324
Conamara Chaos


Conamara Chaos is a region of chaotic terrain on Jupiter's moon Europa. It is named after Connemara () in Ireland due to its similarly rugged landscape. Conamara Chaos is a landscape produced by the disruption of the icy crust of Europa. The region consists of rafts of ice that have moved around and rotated. Surrounding these plates is a lower matrix of jumbled ice blocks which may have been formed as water, slush, or warm ice rose up from below the surface. The region is cited as evidence for a liquid
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Europa (moon)


the same orientation towards Jupiter, the stress patterns should form a distinctive and predictable pattern. However, only the youngest of Europa's fractures conform to the predicted pattern; other fractures appear to occur at increasingly different orientations the older they are. This could be explained if Europa's surface rotates slightly faster than its interior, an effect that is possible due to the subsurface ocean mechanically decoupling Europa's surface from its rocky mantle and the effects of Jupiter's gravity tugging on Europa's outer ice crust. Comparisons of "Voyager"
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Metis (moon)


taken by "Voyager 1" showed Metis only as a dot, and hence knowledge about Metis was very limited until the arrival of the "Galileo" spacecraft. "Galileo" imaged almost all of the surface of Metis and put constraints on its composition by 1998. Although the "Juno" orbiter, which arrived at Jupiter in 2016, has a camera called JunoCam, it is almost entirely focused on observations of Jupiter itself. During close observations of Jupiter, it may capture some distant images of the innermost moons Metis and
1071007
Venus Prime


claim to Forster's discoveries, and only Sparta is able to prevent sabotage. But what is Mays really after? And how will they all react to the discovery of an alien life-form...? World-renowned professor J.Q.R. Forster's expedition to Jupiter's moon has not proven uneventful. In a furious blaze of ice-geysers, the moon's surface rips off to reveal an ancient alien world-ship. But when the world-ship suddenly hurtles through space toward a black hole, Sparta must find out why
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Jupiter Icy Moons Orbiter


The Jupiter Icy Moons Orbiter (JIMO) was a proposed NASA spacecraft designed to explore the icy moons of Jupiter. The main target was Europa, where an ocean of liquid water may harbor alien life. Ganymede and Callisto, which are now thought to have liquid, salty oceans beneath their icy surfaces, were also targets of interest for the probe. JIMO was to have a large number of revolutionary features. Throughout its main voyage to the Jupiter moons, it was to be propelled by an ion propulsion system via either the
16036702
Galilean moons


The rotation of the three inner moons, in contrast, indicates differentiation of their interiors with denser matter at the core and lighter matter above. They also reveal significant alteration of the surface. Ganymede reveals past tectonic movement of the ice surface which required partial melting of subsurface layers. Europa reveals more dynamic and recent movement of this nature, suggesting a thinner ice crust. Finally, Io, the innermost moon, has a sulfur surface, active volcanism and no sign of ice. All this evidence suggests that the nearer a moon
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Jupiter


irregular moons with elliptical and inclined orbits, which are thought to be captured asteroids or fragments of captured asteroids. Irregular moons that belong to a group share similar orbital elements and thus may have a common origin, perhaps as a larger moon or captured body that broke up. Jupiter has a faint planetary ring system composed of three main segments: an inner torus of particles known as the halo, a relatively bright main ring, and an outer gossamer ring. These rings appear to be made of dust, rather than ice as
17937558
Radar for Europa Assessment and Sounding: Ocean to Near-surface


The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a multi-frequency, multi-channel ice penetrating radar system that will be flown on board the "Europa Clipper" mission to Jupiter's moon Europa. REASON investigation will provide the first direct measurements of Europa's ice shell surface character and subsurface structure. The REASON instrument makes innovative use of radar sounding, altimetry, reflectometry, plasma and particles analyses. These investigations will use a dual-frequency radar emitting HF (9 MHz)
8414198
Rajlich's hypothesis


white lamellae are conventionally explained by two other ways. They can be zonal growths or tensile fractures that could be reactivated (healed) in many ways. The first option is less probable, because the lamellae intersect each other. The zonal growths respect the crystallographic planes. The second option is much more probable. Variations of tensile fractures can be found for example in ice. An example can be the Jupiter's moon Europa that has a surface, which is cut by a dense net of fractures. However the tensile fractures and
10469439
Magnetosphere of Jupiter


Ganymedian polar aurorae. Charged particles have a considerable influence on the surface properties of Galilean moons. Plasma originating from Io carries sulfur and sodium ions farther from the planet, where they are implanted preferentially on the trailing hemispheres of Europa and Ganymede. On Callisto however, for unknown reasons, sulfur is concentrated on the leading hemisphere. Plasma may also be responsible for darkening the moons' trailing hemispheres (again, except Callisto's). Energetic electrons and ions, with the flux of the latter being more isotropic, bombard surface ice
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Laplace-P


of the Europa Jupiter System Mission proposed in 2007 by the ESA, that would have studied the Jovian moon system as well as the planet Jupiter. The orbiter would have done several flybys of other Jovian moons before being placed in orbit around Europa. The lander would have researched the ocean underneath the ice sheet of Europa. However, to avoid the damaging effects of Jupiter's radiation belts, the destination of the lander was switched in 2011 from Europa to Ganymede. Ganymede is the largest moon in the Solar System and has an
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Amalthea (moon)


between 88,000 and 170,000 square kilometers, or somewhere near 130,000. Like all other inner moons of Jupiter it is tidally locked with the planet, the long axis pointing towards Jupiter at all times. Its surface is heavily scarred by craters, some of which are extremely large relative to the size of the moon: Pan, the largest crater, measures 100 km across and is at least 8 km deep. Another crater, Gaea, measures 80 km across and is likely twice as deep as Pan. Amalthea has several prominent bright
3192641
Interplanetary spaceflight


produce energy). At least two fundamental non-terrestrial energy sources have been proposed: solar-powered energy generation (unhampered by clouds), either directly by solar cells or indirectly by focusing solar radiation on boilers which produce steam to drive generators; and electrodynamic tethers which generate electricity from the powerful magnetic fields of some planets (Jupiter has a very powerful magnetic field). Water ice would be very useful and is widespread on the moons of Jupiter and Saturn: Oxygen is a common constituent of the moon's crust,
15258558
Shepherd moon


strange "twisted" deformation of rings. Several of Jupiter's small innermost moons, namely Metis and Adrastea, are within Jupiter's ring system and are also within Jupiter's Roche limit. It is possible that these rings are composed of material that is being pulled off these two bodies by Jupiter's tidal forces, possibly facilitated by impacts of ring material on their surfaces. The complex ring system of Saturn has several such satellites. These include Prometheus (F ring), Daphnis (Keeler Gap), Pan (Encke Gap
15382048
Exploration of Jupiter


of the planet, the probes discovered its magnetosphere and its largely fluid interior. The "Voyager 1" and "Voyager 2" probes visited the planet in 1979, and studied its moons and the ring system, discovering the volcanic activity of Io and the presence of water ice on the surface of Europa. "Ulysses" further studied Jupiter's magnetosphere in 1992 and then again in 2000. The "Cassini" probe approached the planet in 2000 and took very detailed images of its atmosphere. The "New Horizons" spacecraft
7764959
Galilean moons


. If a surface data or collection vessel were to land on Io in the future, it would have to be extremely tough (similar to the tank-like bodies of the Soviet Venera landers) to survive the radiation and magnetic fields that originate from Jupiter. Europa (Jupiter II), the second of the four Galilean moons, is the second closest to Jupiter and the smallest at 3121.6 kilometers in diameter, which is slightly smaller than the Moon. The name comes from a mythical Phoenician noblewoman, Europa, who was
12146104
Jupiter


three moons' shapes, with Jupiter's gravity stretching them out as they approach it and allowing them to spring back to more spherical shapes as they swing away. This tidal flexing heats the moons' interiors by friction. This is seen most dramatically in the extraordinary volcanic activity of innermost Io (which is subject to the strongest tidal forces), and to a lesser degree in the geological youth of Europa's surface (indicating recent resurfacing of the moon's exterior). Before the discoveries of the Voyager missions, Jupiter's
17937556
Ganymede (moon)


, it is the seventh satellite and the third of the Galilean moons, the first group of objects discovered orbiting another planet. Ganymede orbits Jupiter in roughly seven days and is in a 1:2:4 orbital resonance with the moons Europa and Io, respectively. Ganymede is composed of approximately equal amounts of silicate rock and water ice. It is a fully differentiated body with an iron-rich, liquid core, and an internal ocean that may contain more water than all of Earth's oceans combined. Its surface is composed of two main
9396018
Extraterrestrial liquid water


on the planet. Because the temperature at the base of the polar cap is estimated at , scientists assume that the water may remain liquid by the antifreeze effect of magnesium and calcium perchlorates. The ice layer covering the lake is composed of water ice with 10 to 20% admixed dust, and seasonally covered by a -thick layer of ice. Scientists' consensus is that a layer of liquid water exists beneath Europa's (moon of Jupiter) surface, and that heat from tidal flexing allows the subsurface ocean to remain liquid.
21093299
Tidal heating


the most volcanically active body in the Solar System: Io, a moon of Jupiter. Io's eccentricity persists as the result of its orbital resonances with the Galilean moons Europa and Ganymede. The same mechanism has provided the energy to melt the lower layers of the ice surrounding the rocky mantle of Jupiter's next closest large moon, Europa. However, the heating of the latter is weaker, because of reduced flexing—Europa has half Io's orbital frequency and a 14% smaller radius; also, while Europa's orbit
12747106
Callisto (moon)


, respectively. These orbital variations cause the axial tilt (the angle between rotational and orbital axes) to vary between 0.4 and 1.6°. The dynamical isolation of Callisto means that it has never been appreciably tidally heated, which has important consequences for its internal structure and evolution. Its distance from Jupiter also means that the charged-particle flux from Jupiter's magnetosphere at its surface is relatively low—about 300 times lower than, for example, that at Europa. Hence, unlike the other Galilean moons, charged-particle
20586387
Europa (moon)


"Jupiter Ganymede Orbiter" led by the ESA were proposed together as an Outer Planet Flagship Mission to Jupiter's icy moons called Europa Jupiter System Mission, with a planned launch in 2020. In 2009 it was given priority over "Titan Saturn System Mission". At that time, there was competition from other proposals. Japan proposed "Jupiter Magnetospheric Orbiter". "Jovian Europa Orbiter" was an ESA Cosmic Vision concept study from 2007. Another concept was "Ice Clipper", which would have used an impactor similar to
20586473
Lucky Starr and the Moons of Jupiter


describes Jupiter IX as being 89 miles in diameter, but its diameter is now thought to be only 23 miles. Part of the novel is also set on Io, the innermost of the Galilean moons. Io is depicted as having a thin atmosphere of methane, and fields of ammonia snow and ice, as well as rivers of liquid ammonia. For six years, Jupiter IX has been the site of a secret project to develop an antigravity, or Agrav, space drive; but the Council of Science learns that information from
8296107
Tidal Moon


Solar System, Jupiter radiates enough heat to create Earthlike environments on the Galilean moons. Ganymede, the third Galilean satellite, has a subarctic climate, large bodies of water, and a six-month rotation period. Due to Jupiter's tidal pull, every spot on Ganymede's surface is inundated with water every three months except a small area of the south pole where the human settlement of Hydropole is located. The Ganymedian natives, the Nympus, grow a mosslike plant called cree which is ordinarily red, but which turns blue
16625157
Meridianiite


history. Remote sensing of other planetary bodies has also indicated the presence of numerous hydrated mineral species, including sulfates, near various planetary surfaces, a prominent example of which is Jupiter’s moon Europa. The relatively smooth, and very young surface of Europa has been interpreted as evidence for a putative ocean beneath the moons icy surface, and is therefore suggestive of liquid brine at depth. Due to the cryospheric conditions present on Europa it is likely that any magnesium sulfate minerals present, and in contact with liquid water, would inherently
8629602
Magnetosphere of Jupiter


torus being the most prominent. In effect, the Galilean moons (mainly Io) serve as the principal plasma sources in Jupiter's inner and middle magnetosphere. Meanwhile, the energetic particles are largely unaffected by the Alfvén wings and have free access to the moons' surfaces (except Ganymede's). The icy Galilean moons, Europa, Ganymede and Callisto, all generate induced magnetic moments in response to changes in Jupiter's magnetic field. These varying magnetic moments create dipole magnetic fields around them, which act to compensate for changes
12093835
Jupiter Icy Moons Explorer


The JUpiter ICy moons Explorer (JUICE) is an interplanetary spacecraft in development by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission is being developed to visit the Jovian system and is focused on studying three of Jupiter's Galilean moons: Ganymede, Callisto, and Europa (excluding the more volcanically active Io) all of which are thought to have significant bodies of liquid water beneath their surfaces, making them potentially habitable environments. The spacecraft is set for launch in June 2022 and
5865932
Wanderers (2014 film)


. We also see adventurers walking across the surface ice on Jupiter's moon Europa, and who, in so doing, might also be walking above extraterrestrial microbes. (Like Saturn's moon Enceladus, astrobiologists are very focused on the possibility that Europa could harbor life.) Another group of adventurers BASE jump off of a cliff on Miranda, the smallest gravitationally-rounded moon orbiting the planet Uranus. The cliff in question, Verona Rupes, may be 5 - 10 kilometers tall. Combined with Miranda's low gravity, Wernquist
2386107
Astrooceanography


Astrooceanography is the study of oceans outside planet Earth. Unlike other planetary sciences like astrobiology, astrochemistry and planetary geology, it only began after the discovery of underground oceans in Saturn's Titan and Jupiter's Ganymede. This field remains speculative until further missions reach the oceans beneath the rock or ice layer of the moons. There are many theories related to celestial bodies in the Solar System, from oceans made of diamond in Neptune to a gigantic ocean of liquid hydrogen that may exist underneath Jupiter's surface. Astrooceanography is closely related to
9158184
Nereid (moon)


model also indicates that the surface roughness of Nereid is very high, likely similar to the Saturnian moon Hyperion. Spectrally, Nereid appears neutral in colour and water ice has been detected on its surface. Its spectrum appears to be intermediate between Uranus's moons Titania and Umbriel, which suggests that Nereid's surface is composed of a mixture of water ice and some spectrally neutral material. The spectrum is markedly different from minor planets of the outer solar system, centaurs Pholus, Chiron and Chariklo, suggesting that Nereid formed around Neptune rather
1765155
Adrastea (moon)


, composition and mass of Adrastea are not known, but assuming that its mean density is like that of Amalthea, around 0.86 g/cm, its mass can be estimated at about 2 kg. Amalthea's density implies that the moon is composed of water ice with a porosity of 10–15%, and Adrastea may be similar. No surface details of Adrastea are known, due to the low resolution of available images. Adrastea is the smallest and second-closest member of the inner Jovian satellite family. It orbits Jupiter at
2387131
Colonization of the outer Solar System


500 rems over a few days is fatal. Jupiter itself, like the other gas giants, is not generally considered a good candidate for colonization. There is no accessible surface on which to land, and the light hydrogen atmosphere would not provide good buoyancy for some kind of aerial habitat as has been proposed for Venus. Io is not ideal for colonization, due to its hostile environment. The moon is under influence of high tidal forces, causing high volcanic activity on the moon. Jupiter's strong radiation belt overshadows Io,
5649885
Geology of Ceres


. Ceres's surface has an albedo of 0.09, which is quite dark compared to the moons in the outer Solar System. This might be a result of the relatively high temperature of Ceres's surface, the maximum temperature with the Sun overhead was estimated from measurements to be on 5 May 1991. In a vacuum, 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. Ceres's oblateness is consistent
19792582
Moons of Uranus


the moons range from 6.7 kg (Miranda) to 3.5 kg (Titania). For comparison, the Moon has a mass of 7.5 kg. The major moons of Uranus are thought to have formed in the accretion disc, which existed around Uranus for some time after its formation or resulted from a large impact suffered by Uranus early in its history. All major moons comprise approximately equal amounts rock and ice, except Miranda, which is made primarily of ice. The ice component may include ammonia and carbon dioxide. Their surfaces
9004799
Ganymede (moon)


single ionized oxygen—O—which fits well with Ganymede's tenuous oxygen atmosphere. In the polar cap regions, at latitudes higher than 30°, magnetic field lines are open, connecting Ganymede with Jupiter's ionosphere. In these areas, the energetic (tens and hundreds of kiloelectronvolt) electrons and ions have been detected, which may cause the auroras observed around the Ganymedian poles. In addition, heavy ions precipitate continuously on Ganymede's polar surface, sputtering and darkening the ice. The interaction between the Ganymedian magnetosphere and Jovian
9396059
Extraterrestrial life


. This is in contrast with the oceans that may be inside larger icy satellites like Ganymede, Callisto, or Titan, where layers of high-pressure phases of ice are thought to underlie the liquid water layer. Hydrogen sulfide has been proposed as a hypothetical solvent for life and is quite plentiful on Jupiter's moon Io, and may be in liquid form a short distance below the surface. The scientific search for extraterrestrial life is being carried out both directly and indirectly. , 3,667 exoplanets in 2,747 systems have been identified,
9556100
Adrastea (moon)


still lie outside its rigid Roche limit. Adrastea is the second-fastest-moving of Jupiter's moons, with an orbital speed of 31.378 km/s. Adrastea is the largest contributor to material in Jupiter's rings. This appears to consist primarily of material that is ejected from the surfaces of Jupiter's four small inner satellites by meteorite impacts. It is easy for the impact ejecta to be lost from these satellites into space. This is due to the satellites' low density and their surfaces lying close to the edge
2387134
List of regions on Io


This is a list of named regions on Jupiter's moon Io. These names have been approved for use by the International Astronomical Union. The features listed below represent a subset of the total known bright regions on Io's surface with many currently not having an officially approved name. These areas are large-scale regions on Io's surface that are notable for their difference in brightness or color from their surroundings. In most cases, these areas are bright terrains, consisting of sulfur dioxide frost/ice fields, suggesting that they
5082041
Tethys (moon)


Tethys (or Saturn III) is a mid-sized moon of Saturn about across. It was discovered by G. D. Cassini in 1684 and is named after the titan Tethys of Greek mythology. Tethys has a low density of 0.98 g/cm, the lowest of all the major moons in the Solar System, indicating that it is made of water ice with just a small fraction of rock. This is confirmed by the spectroscopy of its surface, which identified water ice as the dominant surface material. A small amount of
4822617
Dry ice


of carbon dioxide and it is possible that flakes of dry ice precipitate. Observations from the Uranus flyby by Voyager 2 indicates that dry ice is present on the surface of its large moons Ariel, Umbriel and Titania. Scientist speculate that the magnetic field of Uranus contributes to the generation of CO ice on the surfaces of its moons. Voyager 2 observations of Neptune's moon Triton suggested the presence of dry ice on the surface, though follow up observations indicate that the carbon ices on the surface are carbon monoxide but that the moon
14132431
Trident (spacecraft)


Trident is a space mission concept to the outer planets proposed as a part of NASA's Discovery program. The concept includes flybys of Jupiter and Neptune with a focus on Neptune's largest moon Triton. Triton is the largest moon of Neptune. In 1989, "Voyager 2" flew past the moon at a distance of , and discovered several cryovolcanoes on its surface. Triton is geologically active; its surface is young and has relatively few impact craters. It has a very thin atmosphere. The "Trident" concept was proposed
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Oberon (moon)


presence of water ice is supported by spectroscopic observations, which have revealed crystalline water ice on the surface of the moon. Water ice absorption bands are stronger on Oberon's trailing hemisphere than on the leading hemisphere. This is the opposite of what is observed on other Uranian moons, where the leading hemisphere exhibits stronger water ice signatures. The cause of this asymmetry is not known, but it may be related to impact gardening (the creation of soil via impacts) of the surface, which is stronger on the leading hemisphere.
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Europa (moon)


where it could aid in biological processes. One estimate suggests that, given the turnover rate inferred from the apparent ~0.5 Gyr maximum age of Europa's surface ice, subduction of radiolytically generated oxidizing species might well lead to oceanic free oxygen concentrations that are comparable to those in terrestrial deep oceans. The molecular hydrogen that escapes Europa's gravity, along with atomic and molecular oxygen, forms a gas torus in the vicinity of Europa's orbit around Jupiter. This "neutral cloud" has been detected by both the "Cassini" and
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Lake Vostok


nutrient input, potentially high oxygen concentration and an absence of sunlight. Jupiter's moon Europa and Saturn's moon Enceladus may also harbor lakes or oceans below a thick crust of ice. Any confirmation of life in Lake Vostok could strengthen the prospect for the presence of life on icy moons. Researchers working at Vostok Station produced one of the world's longest ice cores in 1998. A joint Russian, French, and United States team drilled and analyzed the core, which is long. Ice samples from cores drilled close to the
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Falcon Heavy


effort to sample reservoirs of water ice known to exist under the surface. The mission cost as of 2011 was projected to be less than , not including the launch cost. SpaceX 2015 estimation was to the surface of Mars, with a soft retropropulsive landing following a limited atmospheric deceleration using a parachute and heat shield. Beyond the "Red Dragon" concept, SpaceX was seeing potential for Falcon Heavy and Dragon 2 to carry science payloads across much of the Solar System, particularly to Jupiter's moon Europa. SpaceX announced in 2017
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Jupiter in fiction


The planet Jupiter, the largest planet in the solar system, is a popular backdrop for science fiction stories and films. Early works of science fiction used Jupiter itself as a location for stories, but modern science has shown that the planet has no solid surface one could land on and that its atmosphere, temperature, high gravity and intense radiation is hostile to human life. As a result, the Jovian system as a whole, including both the space around Jupiter and its very extensive system of moons, is a more common
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Jupiter Icy Moons Explorer


of the non-water-ice material. Furthermore, JUICE will provide the first subsurface sounding of the moon, including the first determination of the minimal thickness of the icy crust over the most recently active regions. More distant spatially resolved observations will also be carried out for several minor irregular satellites and volcanic moon Io. The main spacecraft design drivers are related to the large distance to the Sun, the use of solar power, and Jupiter's harsh radiation environment. The orbit insertions at Jupiter and Ganymede and the large number
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Jupiter Icy Moons Explorer


ice. The JUICE MAGnetometer experiment will study the subsurface oceans of the icy moons and the interaction of Jovian magnetic field with the magnetic field of Ganymede using a sensitive magnetometer. The Particle Environment Package ("PEP") is a suite of six sensors to study the magnetosphere of Jupiter and its interactions with the Jovian moons. "PEP" will measure positive and negative ions, electrons, exospheric neutral gas, thermal plasma and energetic neutral atoms present in all domains of the Jupiter system from 1 meV to 1 MeV energy.
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Claudia Alexander


moons of Jupiter and the presence of an atmosphere on Ganymede. The discovery of the atmosphere, more precisely a "surface bound exosphere", caused scientists to rethink their assumptions that Ganymede was inactive moon. She was the final project manager for the mission, and oversaw the spacecraft's dive into Jupiter's atmosphere at the mission's conclusion in 2003. Alexander worked as a researcher on diverse topics, including: the evolution and interior physics of comets, Jupiter and its moons, magnetospheres, plate tectonics, space plasma, the
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Exoplanetology


Jupiter-like planets might not be habitable, but they could have habitable moons. The outer edge of the habitable zone is where planets are completely frozen, but planets well inside the habitable zone can periodically become frozen. If orbital fluctuations or other causes produce cooling then this creates more ice, but ice reflects sunlight causing even more cooling, creating a feedback loop until the planet is completely or nearly completely frozen. When the surface is frozen, this stops carbon dioxide weathering, resulting in a build-up of carbon dioxide
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Magnetosphere of Jupiter


by sublimation of water ice from its surfaces, rather than the volcanic activity which produces Io's atmosphere. Ganymede has an internal magnetic field and a magnetosphere of its own. The interaction between this magnetosphere and that of Jupiter produces currents due to magnetic reconnection. The auroral spot associated with Callisto is probably similar to that of Europa, but has only been once as of June, 2019. Normally, magnetic field lines connected to Callisto touch Jupiters atmosphere very close to or along the main auroral oval, making it difficult to detect
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Discovery and exploration of the Solar System


didn't occur until "Viking 1" in 1976), the asteroid 433 Eros in 2001 ("NEAR Shoemaker"), and Saturn's moon Titan ("Huygens") and the comet Tempel 1 ("Deep Impact") in 2005. The "Galileo" orbiter also dropped a probe into Jupiter's atmosphere in 1995; because Jupiter has no physical surface, it was destroyed by increasing temperature and pressure as it descended. To date, only two worlds in the Solar System, the Moon and Mars,
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Callisto (moon)


of the surface, especially in the dark areas, may be close to that seen on D-type asteroids, whose surfaces are made of carbonaceous material. Callisto's battered surface lies on top of a cold, stiff, and icy lithosphere that is between 80 and 150 km thick. A salty ocean 150–200 km deep may lie beneath the crust, indicated by studies of the magnetic fields around Jupiter and its moons. It was found that Callisto responds to Jupiter's varying background magnetic field like a perfectly conducting sphere; that
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List of largest lakes and seas in the Solar System


's moon Io. Subsurface oceans or seas occur on the other Galilean moons of Jupiter, Saturn's moons Titan and Enceladus, and are suspected to exist on the some of Saturn's other moons, the asteroid Ceres, the larger trans-Neptunian objects, and ice planets in planetary systems. Recent analysis of the interior of Ganymede (the largest moon of Jupiter), taking into account the effects of salt, suggests that it and some of the other icy bodies may not have a single interior global ocean but several stacked
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Naboo


comprises five planets, namely "Moth" (Venus type), "Erep" (Venus type), Naboo (Earth type), "Widow" (Mars type) and "Storm" (Jupiter type). The planet Naboo has three moons: Ohma D'un, Rori and Tasia. Tasia, an ice moon, is the only Naboo moon to be seen in the entire Star Wars movie saga (during "The Phantom Menace"). Ohma D'un is a water moon and Rori is a brownish swamp moon
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24 Themis


), the widespread ice on the surface of 24 Themis is somewhat unexpected. The surface ice may be replenished by a sub-surface reservoir of water or impact gardening—a lunar phenomenon in which the moon overturns surface material at a rate of 1  m/ Gyr. An alternative mechanism to explain the presence of water ice on 24 Themis is similar to the hypothesized formation of water on the surface of the Moon by solar wind. Trace amounts of water would be continuously produced by high-energy solar protons impinging oxide minerals present
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Exploration of Jupiter


same announcement also discussed the nature of Jupiter's rings. Light scattering by particles in the rings showed the particles were irregularly shaped (rather than spherical) and likely originated as ejecta from micrometeorite impacts on Jupiter's moons, probably on Metis and Adrastea. On December 19, 2000, the "Cassini" spacecraft captured a very-low-resolution image of the moon Himalia, but it was too distant to show any surface details. The "New Horizons" probe, en route to Pluto, flew by Jupiter for a
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Europa Clipper


Program. "Europa Clipper" will perform follow-up studies to those made by the "Galileo" spacecraft during its eight years in Jupiter orbit, which indicated the existence of a subsurface ocean underneath Europa's ice crust. Plans to send a spacecraft to Europa were initially conceived with projects such as "Europa Orbiter" and "Jupiter Icy Moons Orbiter", in which a spacecraft would be injected into orbit around Europa. However, due to the adverse effects of radiation from Jupiter's magnetosphere in Europan orbit, it was
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Ice cap climate


frozen water, Mars ice caps also have frozen carbon dioxide, commonly known as dry ice. In addition, Mars has seasons similar to Earth. The North Pole of Mars has a permanent water ice cap and a winter-only dry ice cap. On the south pole, both the water and carbon dioxide are permanently frozen. Europa, a moon of Jupiter, is covered with a permanent sheet of water ice, similar to Antarctica. Scientists theorize that it may have sub-glacial lakes similar to those seen in Antarctica
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Umbriel (moon)


from a mean motion resonance than those of Jupiter or Saturn. After Miranda escaped from this resonance (through a mechanism that probably resulted in its anomalously high orbital inclination), its eccentricity would have been damped, turning off the heat source. Umbriel is the third largest and fourth most massive of Uranian moons. The moon's density is 1.39 g/cm, which indicates that it mainly consists of water ice, with a dense non-ice component constituting around 40% of its mass. The latter could be made of
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Europa (moon)


, with an orbital radius of about 670,900 km. With an orbital eccentricity of only 0.009, the orbit itself is nearly circular, and the orbital inclination relative to Jupiter's equatorial plane is small, at 0.470°. Like its fellow Galilean satellites, Europa is tidally locked to Jupiter, with one hemisphere of Europa constantly facing Jupiter. Because of this, there is a sub-Jovian point on Europa's surface, from which Jupiter would appear to hang directly overhead. Europa's prime meridian is a line passing through this
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Jupiter


planet is "Juno", which entered into orbit around Jupiter on July 4, 2016. Future targets for exploration in the Jupiter system include the probable ice-covered liquid ocean of its moon Europa. Astronomers have discovered nearly 500 planetary systems with multiple planets. Regularly these systems include a few planets with masses several times greater than Earth's (super-Earths), orbiting closer to their star than Mercury is to the Sun, and sometimes also Jupiter-mass gas giants close to their star. Earth and its neighbor
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Europa (moon)


the ice. Recent magnetic-field data from the "Galileo" orbiter showed that Europa has an induced magnetic field through interaction with Jupiter's, which suggests the presence of a subsurface conductive layer. This layer is likely a salty liquid-water ocean. Portions of the crust are estimated to have undergone a rotation of nearly 80°, nearly flipping over (see true polar wander), which would be unlikely if the ice were solidly attached to the mantle. Europa probably contains a metallic iron core. Europa is the
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Io (moon)


the leading hemisphere, whereas the side that always faces in the opposite direction is known as the trailing hemisphere. From the surface of Io, Jupiter would subtend an arc of 19.5°, making Jupiter appear 39 times the apparent diameter of Earth's Moon. Io plays a significant role in shaping Jupiter's magnetic field, acting as an electric generator that can develop 400,000 volts across itself and create an electric current of 3 million amperes, releasing ions that give Jupiter a magnetic field inflated to more than twice the size it would
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Amalthea (moon)


, and small size making a landing easy. From the surface of Amalthea, Jupiter would look enormous: 46 degrees across, it would appear roughly 92 times larger than the full moon. Because Amalthea is in synchronous rotation, Jupiter would not appear to move, and would not be visible from one side of Amalthea. The Sun would disappear behind Jupiter's bulk for an hour and a half each revolution, and Amalthea's short rotation period gives it just under six hours of daylight. Though Jupiter would appear 900 times brighter
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Ganymede (moon)


closer to Jupiter, where the subnebula was denser, which explains its shorter formation timescale. This relatively fast formation prevented the escape of accretional heat, which may have led to ice melt and differentiation: the separation of the rocks and ice. The rocks settled to the center, forming the core. In this respect, Ganymede is different from Callisto, which apparently failed to melt and differentiate early due to loss of the accretional heat during its slower formation. This hypothesis explains why the two Jovian moons look so dissimilar, despite
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Venus Prime


Much excitement has arisen throughout the galaxy over the exploration mission to Jupiter's moon, Amalthea. Led by the renowned Professor J.Q.R. Forster, the dangerous expedition will lead its members to the surface of this strange moon – and beyond. It is Sparta's mission to monitor the trip on the part of the Board of Space Control. Her task becomes more threatening when Sir Randolph Mays, Forster's rival and nemesis, "accidentally" crash-lands on Amalthea's surface. Far from innocent, Mays has a plan for laying
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Ariel (moon)


Ariel is the fourth largest of the Uranian moons, and may have the third greatest mass. The moon's density is 1.66 g/cm, which indicates that it consists of roughly equal parts water ice and a dense non-ice component. The latter could consist of rock and carbonaceous material including heavy organic compounds known as tholins. The presence of water ice is supported by infrared spectroscopic observations, which have revealed crystalline water ice on the surface of the moon, which is porous and thus transmits little solar heat to layers
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Nice model


, the orbital distribution of the remaining asteroids does not match observations. In the outer Solar System the impacts onto Jupiter's moons are sufficient to trigger Ganymede's differentiation but not Callisto's. The impacts of icy planetesimals onto Saturn's inner moons are excessive, however, resulting in the vaporization of their ice. After Jupiter and Saturn cross the 2:1 resonance their combined gravitational influence destabilizes the Trojan co-orbital region allowing existing Trojan groups in the L and L Lagrange points of Jupiter and Neptune to escape and new objects from the
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Future of space exploration


on 3 December 2018. JUICE The JUpiter ICy moons Explorer (JUICE) is an interplanetary spacecraft in development by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission is being developed to visit the Jovian system focused on studying three of Jupiter's Galilean moons: Ganymede, Callisto, and Europa (excluding the more volcanically active Io) all of which are thought to have significant bodies of liquid water beneath their surfaces, making them potentially habitable environments. The spacecraft is set for launch
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New Horizons


were scientifically useful on large, distant moons. Emphasis was put on Jupiter's innermost Galilean moon, Io, whose active volcanoes shoot out tons of material into Jupiter's magnetosphere, and further. Out of eleven observed eruptions, three were seen for the first time. That of Tvashtar reached an altitude of up to . The event gave scientists an unprecedented look into the structure and motion of the rising plume and its subsequent fall back to the surface. Infrared signatures of a further 36 volcanoes were noticed. Callisto's surface was
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Our Heavenly Bodies


Jupiter. Depicts a person labouring to crawl on the surface of Jupiter, and giants residing on Jupiter. Saturn's rings as "numberless small bodies", depicts the rings as seen from Saturn, and Saturn's moons; Uranus; Neptune, its discovery, and its one big moon. 6) At the Gates of Infinity () Explains that there is no up or down in space, and attempts to show people in zero gravity; discusses nebulas. The travellers use a flat view screen to look back on Earth
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Terraforming of Venus


CO to bring the atmospheric pressure down to 73.8 bar (carbon dioxide's critical point); and from there reducing the temperature below (carbon dioxide's triple point). Below that temperature, freezing of atmospheric carbon dioxide into dry ice will cause it to deposit onto the surface. He then proposed that the frozen CO could be buried and maintained in that condition by pressure, or even shipped off-world (perhaps to provide greenhouse gas needed for terraforming of Mars or the moons of Jupiter). After this process was
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Thebe (moon)


Thebe ( ; ) also known as , is the fourth of Jupiter's moons by distance from the planet. It was discovered by Stephen P. Synnott in images from the "Voyager 1" space probe taken on March 5, 1979, while making its flyby of Jupiter. In 1983, it was officially named after the mythological nymph Thebe. The second largest of the inner satellites of Jupiter, Thebe orbits within the outer edge of the Thebe gossamer ring that is formed from dust ejected from its surface. It is irregularly shaped
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Jupiter Icy Moons Explorer


reach a resolution of 0.5 km (0.3 mi) observing Ganymede and up to 250 km (155.3 mi) observing Jupiter. The Sub-millimeter Wave Instrument ("SWI") is a spectrometer using a 30 cm (11.8 in) antenna and working in 1080–1275 GHz and 530–601 GHz with spectral resolving power of ~10 that will study Jupiter's stratosphere and troposphere, and the exospheres and surfaces of the icy moons. The GAnymede Laser Altimeter ("GALA") is a laser altimeter with a 20 m (65.6 ft
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Magnetosphere of Jupiter


extensive magnetosphere envelops its ring system and the orbits of all four Galilean satellites. Orbiting near the magnetic equator, these bodies serve as sources and sinks of magnetospheric plasma, while energetic particles from the magnetosphere alter their surfaces. The particles sputter off material from the surfaces and create chemical changes via radiolysis. The plasma's co-rotation with the planet means that the plasma preferably interacts with the moons' trailing hemispheres, causing noticeable hemispheric asymmetries. Close to Jupiter, the planet's rings and small moons absorb high-energy particles
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Titan (moon)


observations also suggests that the ice shell may be substantially rigid. The moons of Jupiter and Saturn are thought to have formed through co-accretion, a similar process to that believed to have formed the planets in the Solar System. As the young gas giants formed, they were surrounded by discs of material that gradually coalesced into moons. Whereas Jupiter possesses four large satellites in highly regular, planet-like orbits, Titan overwhelmingly dominates Saturn's system and possesses a high orbital eccentricity not immediately explained by co-accretion alone.
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Valetudo (moon)


Valetudo (), also known as Jupiter LXII or S/2016 J 2, is a moon of Jupiter. It was discovered by Scott S. Sheppard and his team in data reaching back to 2016, but was not announced until July 17, 2018, via a Minor Planet Electronic Circular from the Minor Planet Center, which also reported the discovery of nine other Jupiter moons. Valetudo has a diameter of about and orbits Jupiter at a distance of about . Its orbital inclination is 34 degrees, and its orbital eccentricity is 0.222. It
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