enceladus vs europa size

Enceladus’ environment is relatively clear of hard radiation. [129] The subsurface layer heating the surface water ice could be an ammonia–water slurry at temperatures as low as 170 K (−103 °C), and thus less energy is required to produce the plume activity. This is an image of the Earth's moon, shown in the center, with several other moons for comparison. [139][142] In addition, models indicate[143] that the large rocky core is porous, allowing water to flow through it, transferring heat and chemicals. [151] Therefore, several robotic missions have been proposed to further explore Enceladus and assess its habitability; some of the proposed missions are: Journey to Enceladus and Titan (JET), Enceladus Explorer (En-Ex), Enceladus Life Finder (ELF), Life Investigation For Enceladus (LIFE), and Enceladus Life Signatures and Habitability (ELSAH). It orbits at 238,000 km from Saturn's center and 180,000 km from its cloud tops, between the orbits of Mimas and Tethys. Cassini found evidence of complex organic molecules that could indicate life beneath the surface of Enceladus. Nevertheless, Europa is the current first target for NASA, with the Europa Clipper due to launch in the early 2020s and a Europa lander to follow a few years later. [63] VIMS also detected simple organic (carbon-containing) compounds in the tiger stripes, chemistry not found anywhere else on Enceladus thus far. Examination of the resulting highest-resolution imagery revealed at least five different types of terrain, including several regions of cratered terrain, regions of smooth (young) terrain, and lanes of ridged terrain often bordering the smooth areas. [99] Cassini also found traces of simple organic compounds in some dust grains,[89][100] as well as larger organics such as benzene (C6H6),[101] and complex macromolecular organics as large as 200 atomic mass units,[30][31] and at least 15 carbon atoms in size. Enceladus, meanwhile, has been studied up close for more than a decade. [6] The surface of Enceladus indicates that the entire moon has experienced periods of enhanced heat flux in the past. [16][19][21] Over 100 geysers have been identified. [56][59] Another example of tectonic features on Enceladus are the linear grooves first found by Voyager 2 and seen at a much higher resolution by Cassini. 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[157][158], The two Voyager spacecraft made the first close-up images of Enceladus. These canyons can be up to 200 km long, 5–10 km wide, and 1 km deep. In particular, Cassini discovered water-rich plumes venting from the south polar region. The Europa Clipper and Europa Lander are envisioned to be launched to Jupiter space by NASA’s planned heavy-lift Space Launch System. For the sake of completeness, both age estimates from, Postberg et al. [159] 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 orbits Saturn every 32.9 hours, fast enough for its motion to be observed over a single night of observation. Voyager 1 was the first to fly past Enceladus, at a distance of 202,000 km on November 12, 1980. [6] Fumaroles are probably the closer analogy, since periodic or episodic emission is an inherent property of geysers. In 2015, the Cassini probe made a close fly-by of Enceladus's south pole, flying within 48.3 km (30 mi) of the surface, as well as through a plume in the process. It is about 500 kilometers (310 mi) in diameter,[5] about a tenth of that of Saturn's largest moon, Titan. [97], The INMS instrument detected mostly water vapor, as well as traces of molecular nitrogen, carbon dioxide,[14] and trace amounts of simple hydrocarbons such as methane, propane, acetylene and formaldehyde. [185][186] NASA will be providing scientific and technical expertise through various reviews, from March 2019 to December 2019. [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. 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 270 K (−3 °C), because pure water requires more energy to melt. ρ q This non-zero eccentricity results in tidal deformation of Enceladus. [119][129], Enceladus is a relatively small satellite composed of ice and rock. Consequently, its surface temperature at noon only reaches −198 °C (−324 °F), far colder than a light-absorbing body would be. 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, "Cassini finds molecular hydrogen in the Enceladus plume: Evidence for hydrothermal processes", "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, 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=991231952, Short description is different from Wikidata, Creative Commons Attribution-ShareAlike License, 'Titan and Enceladus $1B Mission Feasibility' Study, This page was last edited on 29 November 2020, at 00:19.