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[80][81][82], The extent to which cryovolcanism really occurs is a subject of some debate. There are fissures, plains, corrugated terrain and other crustal deformations. Although the heat from radioactivity would decrease over time, the combination of radioactivity and tidal forces from Saturn's gravitational tug could prevent the subsurface ocean from freezing. [40][41], Enceladus is a relatively small satellite composed of ice and rock. At Thanksgiving gatherings, food is shared, leftovers are coveted, and different people have different specialties. Czechowski L. (2015) Mass loss as a driving mechanism of tectonics of Enceladus. https://saturn.jpl.nasa.gov/news/3022/free-samples/, Twitter: https://twitter.com/CassiniSaturn Although Jupiter is a great deal larger in size, its surface gravity is just 2.4 times that of the surface gravity of Earth. The Y-shaped discontinuities, and the northsouth trending tension fractures into which they lead, are correlated with younger terrain with presumably thinner lithospheres. 50-80 km diameter object and Dione, which might have resulted in the resurfacing of its intermediate cratered terrain. In the 1980s some suspected that Enceladus is the main source of particles for the ring. Many of these fractures are found in bands cutting across cratered terrain. [63] Viscous relaxation allows gravity, over geologic time scales, to deform craters and other topographic features formed in water ice, reducing the amount of topography over time. It includes activities that can be done at home as well as videos, animations, stories, and articles. Our 2021 round-up of NASA planetary science is packed with the years most spectacular images, ground-breaking discoveries, and incredible mission events. [116][117], During the flyby of July 14, 2005, the Composite Infrared Spectrometer (CIRS) found a warm region near the south pole. [91][89] Subsequent radioactive and tidal heating would raise the temperature of the core to 1,000 K, enough to melt the inner mantle. [29], These geyser observations, along with the finding of escaping internal heat and very few (if any) impact craters in the south polar region, show that Enceladus is currently geologically active. This geologic diversity contrasts with the ancient, heavily cratered surface of Mimas, another moon of Saturn slightly smaller than Enceladus. The November 2005 images showed the plume's fine structure, revealing numerous jets (perhaps issuing from numerous distinct vents) within a larger, faint component extending out nearly 500km (310mi) from the surface. It completes one orbit every 32.9 hours within the densest part of Saturn's E Ring. [150][151][152] Molecular hydrogen (H2), a geochemical source of energy that can be metabolized by methanogen microbes to provide energy for life, could be present if, as models suggest, Enceladus's salty ocean has an alkaline pH from serpentinization of chondritic rock.[113][114][115]. The Moon has only 17% of our Earth's gravity. more radiogenic heating or a more eccentric orbit in the past). Modeling suggests that for Enceladus, both a 'basic' low-energy thermal state with little internal temperature gradient, and an 'excited' high-energy thermal state with a significant temperature gradient, and consequent convection (endogenic geologic activity), once established, would be stable. [93], Evidence of liquid water on Enceladus began to accumulate in 2005, when scientists observed plumes containing water vapor spewing from its south polar surface,[6][94] with jets moving 250kg of water vapor every second[94] at up to 2,189km/h (1,360mph) into space. The researchers suggested that the compounds on Enceladus could be precursors for "biologically relevant organic compounds". High angular momentum of Moon/Earth system (combined = 1 rotation/5 hours) Density of Moon - 3 gm/cm 3 , depleted in Fe compared to Earth; Strong volatile depletion; Primordial magma ocean (high temperatures) Rotational fission a. George Darwin hypothesized in 1880 that the Moon formed from the outer layers of a rapidly spinning proto-Earth. . The study found that nitrogen-bearing and oxygen-bearing amines were likely present, with significant implications for the availability of amino acids in the internal ocean. About as wide as Arizona, Enceladus orbits Saturn at a distance of 148,000 miles (238,000 kilometers) between the orbits of two other moons, Mimas and Tethys. [6] Enceladus is only one-seventh the diameter of Earth's Moon. Our study suspects a relatively low-velocity (5 km/s) collision between a c.a. Design & Development: [47] Tidal dissipation of Enceladus's ice crust is significant because Enceladus has a subsurface ocean. 46th Lunar and Planetary Science Conference 2030.pdf. [63] Given the level of resurfacing found on Enceladus, it is clear that tectonic movement has been an important driver of geology for much of its history. On Oct. 9, 2008, just after coming within 25 kilometers (15.6 miles) of the surface of Enceladus, NASA's Cassini captured this stunning mosaic as the spacecraft sped away from this geologically active moon of Saturn. [123][124][125][126] A 2007 study predicted the internal heat of Enceladus, if generated by tidal forces, could be no greater than 1.1 gigawatts,[127] but data from Cassini's infrared spectrometer of the south polar terrain over 16 months, indicate that the internal heat generated power is about 4.7 gigawatts,[127] and suggest that it is in thermal equilibrium. Tiger Lu, Hanno Rein, Daniel Tamayo, Sam Hadden, Rosemary Mardling, Sarah C. Millholland, Gregory Laughlin. [56], Visual confirmation of venting came in November 2005, when ISS imaged geyser-like jets of icy particles rising from Enceladus's south polar region. [67] Consequently, the moon's ellipsoid shape would have adjusted to match the new orientation. Without the short-lived variety, Enceladus's complement of long-lived radionuclides would not have been enough to prevent rapid freezing of the interior, even with Enceladus's comparatively high rockmass fraction, given its small size. [6] However, the current shape also supports the possibility that Enceladus is not in hydrostatic equilibrium, and may have rotated faster at some point in the recent past (with a differentiated interior). Tiny Enceladus has a global saltwater ocean that sprays into space as a plume of icy particles. While the process of moon formation around Saturn, with it's huge gravity and immense ring system, is far different from that on Earth, this development is no less fascinating. They generally have low relief and have far fewer craters than in the cratered terrains, indicating a relatively young surface age. [37] Prior to the Voyager missions the view of Enceladus improved little from the dot first observed by Herschel. A mass spectrometer on the craft detected molecular hydrogen (H2) from the plume, and after months of analysis, the conclusion was made that the hydrogen was most likely the result of hydrothermal activity beneath the surface. Pictures from the Voyager spacecraft in the 1980s indicated that although this moon is smallonly about 310 miles (500 kilometers) across its icy surface is remarkably smooth in some places, and bright white all over. Rather than being covered in low-relief ridges, this region is covered in numerous criss-crossing sets of troughs and ridges, similar to the deformation seen in the south polar region. [91] Gravity measurements by Cassini show that the density of the core is low, indicating that the core contains water in addition to silicates. "Plume and surface composition of Enceladus", p. 129130, 148, 156; Lunine et al. mimas enceladus tethys web nov 21 2022 specialties we re planet fitness the judgement . This may be quite dangerous. One-kilometer high domes have also been observed. A later study from 2019 estimated that the ocean is around one billion years old. Our understanding of Neptune's magnetosphere and aurora is limited almost entirely to radio, UV and in-situ observations made by Voyager 2. Despite its small size, Enceladus has a wide range of surface features, ranging from old, heavily cratered regions to young, tectonically deformed terrain. As of 2006 there were two theories for what could cause such a shift in shape: the orbit of Enceladus may have migrated inward, leading to an increase in Enceladus's rotation rate. [33] Ongoing research on Cassini data suggests that Enceladus's hydrothermal environment could be habitable to some of Earth's hydrothermal vent's microorganisms, and that plume-found methane could be produced by such organisms.[34][35]. Because no ammonia was initially found in the vented material by INMS or UVIS, which could act as an antifreeze, it was thought such a heated, pressurized chamber would consist of nearly pure liquid water with a temperature of at least 270K (3C), because pure water requires more energy to melt. [157][158] The presence of a wide range of organic compounds and ammonia indicates their source may be similar to the water/rock reactions known to occur on Earth and that are known to support life. A size comparison of Enceladus against the British Isles. Enceladus is named after the giant Enceladus of Greek mythology. 16, EGU2014-9492-1", "A Perspective on Life on Enceladus: A World of Possibilities", "Warm Oceans on Saturn's Moon Enceladus Could Harbor Life", Habitability of Enceladus: Planetary Conditions for Life, "Ocean on Saturn's moon Enceladus could be rich in a key ingredient for life", "Abundant phosphorus expected for possible life in Enceladus's ocean", "Conditions for Life Detected on Saturn Moon Enceladus", "NASA: Ocean on Saturn moon may possess life-sustaining hydrothermal vents", "NASA finds more evidence that the ocean on Enceladus could support alien life", "NASA Missions Provide New Insights into 'Ocean Worlds', "NASA finds ingredients for life spewing out of Saturn's icy moon Enceladus", "Enceladus: Evolution and Possible Relationship to Saturn's E-ring", "Saturn's Geyser Moon Shines in Close Flyby Views", "Cassini Completes Final Close Enceladus Flyby", "Deepest-Ever Dive Through Enceladus Plume Completed", "Cassini Images of Enceladus Suggest Geysers Erupt Liquid Water at the Moon's South Pole", "The search for life from Venus to the outer solar system", "Signs of Europa Plumes Remain Elusive in Search of Cassini Data", "A lander mission to probe subglacial water on Saturn's moon Enceladus for life", "Exciting New 'Enceladus Explorer' Mission Proposed to Search for Life", "Searching for life in the depths of Enceladus", "Diverse destinations considered for new interplanetary probe", "Saturn Moon Enceladus Eyed for Sample-Return Mission", "TandEM (Titan and Enceladus Mission) Workshop", "Private mission may get us back to Enceladus sooner than NASA", "NASA to support initial studies of privately funded Enceladus mission", NASA to support initial studies of privately funded Enceladus mission, Billionaire aims to jump-start search for alien life and rewrite rules of space exploration, A different trajectory for funding space science missions, "Planetary science decadal endorses Mars sample return, outer planets missions", Titan and Enceladus $1B Mission Feasibility Study, "Planetary Science Decadal Survey Enceladus Orbiter", "Discovery Missions for an Icy Moon with Active Plumes", "IceMole Drill Built to Explore Saturn's Icy Moon Enceladus Passes Glacier Test", "LIFE Enceladus Plume Sample Return via Discovery", "LIFE: Life Investigation For Enceladus A Sample Return Mission Concept in Search for Evidence of Life", "Explorer of Enceladus and Titan (E2T): Investigating the habitability and evolution of ocean worlds in the Saturn system", "Cassini: The legend and legacy of one of NASA's most prolific missions", Paul Schenk's 3D images and flyover videos of Enceladus and other outer solar system satellites, Images of Enceladus at JPL's Planetary Photojournal, https://en.wikipedia.org/w/index.php?title=Enceladus&oldid=1142444823, 'Titan and Enceladus $1B Mission Feasibility' Study, This page was last edited on 2 March 2023, at 12:01. The Cassini spacecraft has been gone for a year now, but the science continues. A handful of worlds are thought to have liquid water oceans beneath their frozen shell, but Enceladus sprays its ocean out into space where a spacecraft can sample it. Shortest mean distance between Earth and Enceladus is about 1,279.586 million kilometer or about 8.5534 AU (astronomical unit) Earth is 3rd planet in our solar system. [60], Impact cratering is a common occurrence on many Solar System bodies. We nd [165] Images acquired from this distance had very poor spatial resolution, but revealed a highly reflective surface devoid of impact craters, indicating a youthful surface. It builds on the experience gained from two less ambitious previous proposals, led by American scientists, the Journey to Enceladus (JET) in 2010 and the Enceladus Life Finder (ELF) in 2014. This area, reaching as far north as 60 south latitude, is covered in tectonic fractures and ridges. [22] Some of the water vapor falls back as "snow"; the rest escapes and supplies most of the material making up Saturn's Ering. [57]), Enceladus orbiting within Saturn's Ering, Enceladus geyser tendrils - comparison of images ("a";"c") with computer simulations, Enceladus south polar region - locations of most active tendril-producing geysers, Voyager 2 was the first spacecraft to observe Enceladus's surface in detail, in August 1981. Moore Boeck, A 3D model of Saturn's moon Enceladus, an icy moon with a hidden subsurface ocean. However, the observed 4.7 gigawatts heat flux is enough to power the cryovolcanism without the presence of ammonia. [58] However, based on the effects of Enceladus's gravity on Cassini, its mass was determined to be much higher than previously thought, yielding a density of 1.61 g/cm3. https://saturn.jpl.nasa.gov/news/3020/the-moon-with-the-plume/ [140], It has been suggested that for an icy satellite the size of Mimas or Enceladus to enter an 'excited state' of tidal heating and convection, it would need to enter an orbital resonance before it lost too much of its primordial internal heat. Only a small fraction of the material ends up in the ring, however, with most of it falling like snow back to the moons surface, which helps keep Enceladus bright white. Because Enceladus reflects so much sunlight, the surface temperature is extremely cold, about minus 330 degrees Fahrenheit (minus 201 degrees Celsius). [79], Much of the plume activity consists of broad curtain-like eruptions. Like many satellites of Saturn discovered prior to the Space Age, Enceladus was first observed during a Saturnian equinox, when Earth is within the ring plane. Initial mass estimates from the Voyager program missions suggested that Enceladus was composed almost entirely of water ice. Since the ocean in Enceladus supplies the jets, and the jets produce Saturns E ring, to study material in the E ring is to study Enceladus ocean. In addition, an increase in the power of ion cyclotron waves near the orbit of Enceladus was observed, which was further evidence of the ionization of neutral gas. In 2023, NASAs Volatiles Investigating Polar Exploration Rover (VIPER) will land near the western edge of the Nobile Crater at the Moons South Pole. Enceladus measures about 500 km (310 miles) in diameter and orbits Saturn in a prograde, nearly circular path at a mean distance of 238,020 km (147,899 miles). [12], Observations during three flybys on February 17, March 9, and July 14, 2005, revealed Enceladus's surface features in much greater detail than the Voyager 2 observations. It is a little more than 9.5 times further from the sun than is the earth, and almost twice as distant from the sun as Jupiter. [170] Cassini's extended mission included seven close flybys of Enceladus between July 2008 and July 2010, including two passes at only 50km in the later half of 2008. Voyager 2 made its closest approach to Saturn on Aug. 25, 1981. For scientists, it's also one of the most interesting places in our solar system. [160][161][162], The presence of ample hydrogen in Enceladus's ocean means that microbes if any exist there could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water. Ganymede Ranking from least to most, the list includes: Enceladus, Triton, Dione, Pluto, Earth, with Europa, Callisto, Titan and Ganymede have the most liquid water by volume. [110], The mass spectrometer detected molecular hydrogen (H2) which was in "thermodynamic disequilibrium" with the other components,[111] and found traces of ammonia (NH3). From gravity measurements based on the Doppler effect and the magnitude of the moons very slight wobble as it orbits Saturn, scientists determined that the jets were being supplied by a global ocean inside the moon. However, for Enceladus to still be active, part of the core must have also melted, forming magma chambers that would flex under the strain of Saturn's tides. These discoveries prompted the adjustment of Cassini's flight plan to allow closer flybys of Enceladus, including an encounter in March 2008 that took it to within 48km of the surface. We performed mission simulations to study the sensitivity of single-spacecraft and dual-spacecraft congurations to static gravity and tidal Love numbers of Enceladus. [139], The significantly higher density of Enceladus relative to Mimas (1.61 vs. 1.15 g/cm3), implying a larger content of rock and more radiogenic heating in its early history, has also been cited as an important factor in resolving the Mimas paradox. It was discovered in 1789 by William Herschel and named after the Greek mythological giant Enceladus. Compared to Earth's peaceful moon, Jupiter's moon Io may come as a surprise. Design & Development: (2005) suggested that Iapetus and the other icy satellites of Saturn formed relatively quickly after the formation of the Saturnian subnebula, and thus were rich in short-lived radionuclides. This non-zero eccentricity results in tidal deformation of Enceladus. Scientists think that the moons ice shell may be as thin as half a mile to 3 miles (1 to 5 kilometers) at the south pole. Only its orbital characteristics were known, with estimations of its mass, density and albedo. The plumes of Enceladus were observed to be continuous to within a factor of a few. Heating in Enceladus has occurred through various mechanisms ever since its formation. The gravitational tug of a planetary body, such as Enceladus, alters a spacecraft's flight path ever so slightly. For information on the Earth, see the Earth Fact Sheet. (Remember Enceladus, just much smaller). Now it's one of the fastest-growing fields in astronomy with thousands of exoplanets discovered to date, and the number is rising fast. Scientists have observed water plumes erupting from Enceladus, and believe similar plumes can be found on Europa. By measuring the effect of such deflections on the frequency of Cassini's signal. "[75] Previous models suggest that resonant perturbations of Dione could provide the necessary periodic eccentricity changes to maintain the subsurface ocean of Enceladus, if the ocean contains a substantial amount of ammonia. Enceladus Diagrams Enceladus size compared to the Moon and Earth However, unlike those seen on Ganymede, grooved topography on Enceladus is generally more complex. The shadows cast by the roughness of the Moons surface create small cold spots for water ice to accumulate even during the harsh lunar daytime. [190] The spacecraft would be low-cost, low mass, and would be launched at high speed on an affordable rocket. [122] The present-day radiogenic heating rate is 3.21015 ergs/s (or 0.32 gigawatts), assuming Enceladus has a composition of ice, iron and silicate materials. It is the ninth-largest object in the Solar System and the largest without a substantial atmosphere. [105][106][147] This indicates that hydrothermal activity an energy source may be at work in Enceladus's subsurface ocean. Voyager 2 passed closer to Enceladus (87,010km) on August 26, 1981, allowing higher-resolution images to be obtained. Enceladus was discovered by William Herschel on August 28, 1789, during the first use of his new 1.2m (47in) 40-foot telescope, then the largest in the world, at Observatory House in Slough, England. Enceladus is 1,272,000,000km = 0.00013445ly away from Earth Physical Properties Enceladus' surface made up of mostly of nearly pure water ice except near its south pole, where there are light organics, CO2, and amorphous and crystalline water ice, mostly in the region called the "tiger stripes." Enceladus is the sixth-largest moon of Saturn (19th largest in the Solar System).It is about 500 kilometers (310 miles) in diameter, about a tenth of that of Saturn's largest moon, Titan.Enceladus is mostly covered by fresh, clean ice, making it one of the most reflective bodies of the Solar System. doi:10.1016/j.pss.2014.09.010. For decades, scientists didnt know why. From deep below the soil at Earth's polar regions to Pluto's frozen heart, ice exists all over the solar system.and beyond. Given the results from the Voyager 2 images, Enceladus was considered a priority target by the Cassini mission planners, and several targeted flybys within 1,500km of the surface were planned as well as numerous, "non-targeted" opportunities within 100,000km of Enceladus. [102], The Cassini spacecraft flew through the southern plumes on several occasions to sample and analyze its composition. With a mean radius of 252 km, Enceladus is equivalent in size to 0.0395 Earths (or 0.1451 Moons). The "salty" particles are heavier and mostly fall back to the surface, whereas the fast "fresh" particles escape to the E ring, explaining its salt-poor composition of 0.52% of sodium salts by mass. [76][77][78] This is consistent with geophysical calculations which predict the south polar fissures are under compression near periapsis, pushing them shut, and under tension near apoapsis, pulling them open. [58] Results from Cassini suggest that tectonics is the dominant mode of deformation on Enceladus, including rifts, one of the more dramatic types of tectonic features that were noted. [6] Enceladus orbits within the densest part of Saturn's E ring, the outermost of its major rings, and is the main source of the ring's material composition. [68] Here the "blue" ice is on a flat surface, indicating that the region is young enough not to have been coated by fine-grained water ice from the E ring. Such features are geologically young, because they cut across other tectonic features and have sharp topographic relief with prominent outcrops along the cliff faces. This area is on the opposite side of Enceladus from Sarandib and Diyar Planitiae, suggesting that the placement of these regions is influenced by Saturn's tides on Enceladus. The dissipated heat resulting from this deformation is the main heating source for Enceladus's geologic activity. Data collected by NASA's Cassini spacecraft hints at an unknown methane-producing process at work in the moon's hidden ocean. Jupiter's gravity is 2.5 times stronger than Earth's gravity. 5 times the force of gravity compared to Earth. enceladus gravity compared to earthsri lanka weather february celsius. JPL's lucky peanuts are an unofficial tradition at big mission events. [43][44], Size comparison of Earth, the Moon, and Enceladus. NASAs Hubble Space Telescope has completed this year's grand tour of the outer solar system. The combined analysis of imaging, mass spectrometry, and magnetospheric data suggests that the observed south polar plume emanates from pressurized subsurface chambers, similar to Earth's geysers or fumaroles. Gravity on Mercury: With a mean radius of about 2,440 km and a mass of 3.30 1023 kg, Mercury is approximately 0.383 times the size of Earth and only 0.055 as massive. [88][89] These radionuclides, like aluminium-26 and iron-60, have short half-lives and would produce interior heating relatively quickly. Cassini observations of the Samarkand Sulci have revealed dark spots (125 and 750 m wide) located parallel to the narrow fractures. Planetary and Space Science. Organic compounds have been found in the plumes rising from the subsurface ocean on Enceladus, adding to the evidence that one of Saturn's most intriguing moons should be explored further. NASA's Europa Clipper is on the Case, NASA's Lunar Reconnaissance Orbiter Images Saturn, Hubble's Grand Tour of the Outer Solar System, Giving and Receiving: A Mission Tradition, NASA Outlines Challenges, Progress for Artemis Moon Missions, NASA's Artemis Rover to Land Near Nobile Region of Moon's South Pole, NASA to Announce Landing Site for Artemis Lunar Robotic Rover, September 2021: The Next Full Moon is the Harvest Moon; the Fruit or Barley Moon, 40 Years On, Remembering Voyager's Legacy at Saturn, NASA Study Highlights Importance of Surface Shadows in Moon Water Puzzle, Hubble Finds First Evidence of Water Vapor at Jupiter's Moon Ganymede, NASA Awards Launch Services Contract for Europa Clipper Mission, July 2021: The Next Full Moon is the Buck Moon, Thunder Moon, Hay Moon, Mead Moon, Glenn Researchers Study New, Futuristic Concept to Explore Titan, Probing for Life in the Icy Crusts of Ocean Worlds. Voyager 1 was the first to fly past Enceladus, at a distance of 202,000km on November 12, 1980. In addition, to the extent that tides produce heat along fractures, libration may affect the magnitude and distribution of such tidal shear heating. Enceladus's gravity (-150 degrees C): 49.08; Atmosphere stability for water molecules: Earth's gravity (15 degrees C): 7.320; . The area is also littered with house-sized ice boulders and regions carved by tectonic patterns unique to this region of the moon. 243 Ida, an asteroid designated as a minor planet, has a moon, measuring just 0.99 miles (1.6 km) across on its longest axis. Enceladus is named after the giant Enceladus of Greek mythology. [127][137], Mimas, the innermost of the round moons of Saturn and directly interior to Enceladus, is a geologically dead body, even though it should experience stronger tidal forces than Enceladus. Saturn's moon, Enceladus, is a small, icy world. NASA-funded scientists have discovered shaded locations within pits on the Moon that always hover around a comfortable 63 F. From deep below the soil at Earths polar regions to Plutos frozen heart, ice exists all over the solar systemand beyond. Unlike the magnetometer, UVIS failed to detect an atmosphere above Enceladus during the February encounter when it looked over the equatorial region, but did detect water vapor during an occultation over the south polar region during the July encounter.[16]. While Earth's history of magmatism is known to significantly contribute to the evolution of its atmosphere, Enceladus' gravity at the surface, a hundred times smaller, rather enables its volcanic activity to shape its orbital environment. [194], View of trailing hemisphere in natural color, View of Enceladus's orbit from the side, showing Enceladus in relation to Saturn's E ring, Eruptions on Enceladus look like discrete jets, but may be "curtain eruptions" instead, Enceladus possibility of fresh ice detected (September 18, 2020), Enceladus Infrared map view (September 29, 2020), Enceladus (artist concept; February 24, 2020), Enceladus close flyby (October 28, 2015), Enceladus final flyby (December 19, 2015), Photograph of Enceladus, taken by the narrow-angle camera of the, Without samples to provide absolute age determinations, crater counting is currently the only method for determining surface age on most planetary surfaces. [26][97][98][154][155][156] Geochemical modeling results concerning not-yet-detected phosphorus indicate the moon meets potential abiogenesis-requirements. From these samples, scientists have determined that Enceladus has most of the chemical ingredients needed for life, and likely has hydrothermal vents spewing out hot, mineral-rich water into its ocean. [50][51] Readings from Cassini's 2005 passage suggested that cryovolcanism, where water and other volatiles are the materials erupted instead of silicate rock, had been discovered on Enceladus. The smooth plains, which Voyager 2 had observed, resolved into relatively crater-free regions filled with numerous small ridges and scarps. [6] The surface of Enceladus indicates that the entire moon has experienced periods of enhanced heat flux in the past. Ridges have also been observed on Enceladus, though not nearly to the extent as those seen on Europa. The Jovian moon has hundreds of volcanoes and is considered the most active moon in the solar system, sending plumes of . And enormous Titan may have a subsurface water ocean of its own. VIMS detected crystalline water ice in the stripes, suggesting that they are quite young (likely less than 1,000 years old) or the surface ice has been thermally altered in the recent past.