what appears to have caused the extensive cracking and streaking of the surface of europa?

Europa

Louise M. Prockter , Robert T. Pappalardo , in Encyclopedia of the Solar System (Third Edition), 2014

3.3 Tidal Heating

Europa's resonance with siblings Io and Ganymede causes it to take a slightly eccentric orbit (e = 0.0094). This eccentricity causes Europa to move closer to and farther from Jupiter (at perijove and apojove, respectively) every bit it moves along its 85 h orbit, causing the satellite to undergo increasing and decreasing gravitational pull from Jupiter. At the same time, Europa undergoes libration, its tidal bulge rocking from side to side as Europa orbits Jupiter. If an ocean is nowadays decoupling the beat (equally described below), Europa could deform by up to ∼thirty 1000 over each orbital menses, and the dissipation of strain energy resulting from this deformation would crusade the interior to warm. Dissipation of tidal energy can occur in several ways, such as past friction forth faults, turbulence at liquid/solid boundaries, and viscoelastic heating at the scale of individual ice or mineral grains. It is likely that a great degree of tidal energy is currently dissipated nigh the base of Europa's icy shell, merely to a higher place the interface between the water ice and the underlying liquid bounding main, where the water ice is warmest and almost deformable on the timescale of the satellite's orbit. Combined with radiogenic heating from the deep interior, this regular input of energy is believed to be sufficient to keep Europa'south body of water liquid; additional heating might result if at that place is also tidal dissipation in the rocky mantle.

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Europa

Louise M. Prockter , Robert T. Pappalardo , in Encyclopedia of the Solar System (2nd Edition), 2007

3.3 Tidal Heating

Europa'due south Laplace resonance with siblings Io and Ganymede causes information technology to have a slightly eccentric orbit (due east = 0.0094). This eccentricity causes Europa to move closer to and farther from Jupiter (at perijove and apojove, respectively) every bit it moves along its 85 hour orbit, causing the satellite to undergo increasing and decreasing gravitational pull from Jupiter. At the same time, Europa undergoes libration as information technology orbits Jupiter, its tidal bulge necessarily rocking from side to side as the moon's orbital velocity changes only the rotation rate stays constant. Europa deforms by ∼one–30 thousand over each orbital period (Fig. three), and the dissipation of strain energy resulting from this deformation causes the interior to warm. Dissipation of tidal energy tin can happen in several ways, such every bit by friction along faults, turbulence at liquid–solid boundaries, and viscoelastic heating at the scale of private ice grains. It is likely that a great degree of tidal free energy is currently dissipated at the base of Europa's icy shell, simply above the interface between the ice and the underlying liquid sea, where the ice is warmest and well-nigh deformable on the time scale of the satellite'due south orbit. This regular input of energy is believed to be sufficient to keep Europa'southward ocean liquid.

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Astrobiology

C.P. McKay , in Encyclopedia of Ecology, 2008

Europa

Europa is ane of the Galilean moons of Jupiter and is interesting for astrobiology because of the presence of an ocean nether its icy surface. There are two lines of evidence that point an ocean: the frozen surface of iceberg-similar features and the magnetic disturbance every bit Europa moves through the Jovian field. The former indicates the depth to the ocean is well-nigh 10 km and the latter indicates that the ocean is still present today.

Life on World may accept originated in hot deep sea vents and Europa may have had similar deep sea vents, thus it is plausible that life may have also originated in Europa's seas. The aforementioned hot circulation could provide a continued free energy source for life. Europa is more likely than Mars to have been free of whatsoever meteorites from Earth, so if there is life information technology is less likely to have been transported from Earth, hence more than likely to be a second genesis.

The ocean of Europa is difficult to admission but if the linear features seen on the surface are cracks then these may exist locations where h2o from the body of water has been deposited on the surface. Any life in the water would remain, frozen and dead, on the surface. Samples of this fabric might allow united states of america to investigate the biochemistry and genetics of a second example of life.

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Astrobiology

Christopher P. McKay , Wanda L. Davis , in Encyclopedia of the Solar Organization (Third Edition), 2014

6.four.one Europa

Europa, 1 of the moons of Jupiter, appears to be an airless ice-shrouded world. However, theoretical calculations suggest that under the water ice surface of Europa in that location may be a layer of liquid water sustained by tidal heating as Europa orbits Jupiter. The Galileo Spacecraft imaging showed features in the ice consequent with a subsurface bounding main and the magnetometer indicated the presence of a global layer of slightly salty liquid water. The surface of Europa is crisscrossed by streaks that are slightly darker than the remainder of the icy surface. If there is an ocean beneath a relatively sparse ice layer and then these streaks may correspond cracks where the water has come up to the surface. ( Run across Small-scale Satellites.)

At that place are many ecosystems on World that thrive and grow in h2o that is continuously covered past ice. These are found in both the Arctic and Antarctic regions. In addition to the polar oceans where bounding main ice diatoms perform photosynthesis nether the ice encompass, there are perennially ice-covered lakes in the Antarctic continent in which microbial mats based on photosynthesis are found in the h2o beneath a 4 thou ice comprehend. The light penetrating these thick water ice covers is minimal—about 1% of the incident lite. Using these World-based systems as a guide it is possible that sunlight penetrating through the cracks (the observed streaks) in the water ice of Europa could support a transient photosynthetic community. Alternatively, if at that place are hydrothermal sites on the bottom of the Europan body of water it may be possible that chemosynthetic life could survive at that place—by analogy to life at hydrothermal vent sites at the bottom of the Earth's oceans. The biochemistry of hydrothermal sites on Earth does depend on O₂ produced at the Earth'south surface. On Europa, a chemical scheme like that suggested for subsurface life on Mars would be appropriate (H₂ + CO₂).

The main problem with life on Europa is the question of its origin. Lacking a complete theory for the origin of life, and lacking whatever laboratory synthesis of life, we have to base our understanding of the origin of life on other planets on analogy with the Earth. It has been suggested that hydrothermal vents may have been the site for the origin of life on Globe and in this case the prospects for life in a putative ocean on Europa are improved. Notwithstanding, the early on Globe independent many environments other than hydrothermal vents, such as surface hot springs, volcanoes, lake and ocean shores, tidal pools, and salt flats. If any of these environments were the locale for the origin of the first life on Earth then the case for an origin on Europa is weakened considerably.

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Astrobiology

Christopher P. McKay , Wanda L. Davis , in Encyclopedia of the Solar Organization (2nd Edition), 2007

half dozen.iv.1 EUROPA

Europa, one of the moons of Jupiter, appears to be an airless ice-shrouded world. All the same, theoretical calculations propose that under the ice surface of Europa there may exist a layer of liquid h2o sustained past tidal heating as Europa orbits Jupiter. The Galileo spacecraft imaging showed features in the ice consistent with a subsurface bounding main and the magnetometer indicated the presence of a global layer of slightly salty liquid h2o. The surface of Europa is criss-crossed by streaks that are slightly darker than the balance of the icy surface. If at that place is an ocean below a relatively thin ice layer, these streaks may represent cracks where the water has come to the surface. [Come across Planetary Satellites.]

There are many ecosystems on Earth that thrive and grow in h2o that is continuously covered past water ice; these are establish in both the Arctic and Antarctic regions. In addition to the polar oceans where body of water ice diatoms perform photosynthesis under the ice cover, in that location are perennially ice-covered lakes in the Antarctic continent in which microbial mats based on photosynthesis are constitute in the water beneath a 4-grand water ice cover. The calorie-free penetrating these thick ice covers is minimal, almost ane% of the incident light. Using these Earth-based systems every bit a guide, information technology is possible that sunlight penetrating through the cracks (the observed streaks) in the ice of Europa could back up a transient photosynthetic community. Alternatively, if there are hydrothermal sites on the bottom of the Europan ocean, it may be possible that chemosynthetic life could survive there—past analogy to life at hydrothermal vent sites at the lesser of the World's oceans. The biochemistry of hydrothermal sites on Earth does depend on O ₂ produced at the Earth's surface. On Europa, a chemical scheme like that suggested for subsurface life on Mars would exist advisable (H ₂ + CO₂).

The main problem with life on Europa is the question of its origin. Lacking a complete theory for the origin of life, and lacking any laboratory synthesis of life, we must base of operations our understanding of the origin of life on other planets on analogy with the World. It has been suggested that hydrothermal vents may have been the site for the origin of life on Earth and if this is the case improves the prospects for life in a putative body of water on Europa. All the same, the early Earth contained many environments other than hydrothermal vents, such every bit surface hot springs, volcanoes, lake and sea shores, tidal pools, and salt flats. If any of these environments were the locale for the origin of the showtime life on Earth, the instance for an origin on Europa is weakened considerably.

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SOLAR SYSTEM | Jupiter, Saturn and Their Moons

P. Moore , in Encyclopedia of Geology, 2005

Europa

Europa is just slightly smaller than Io, and rather further from Jupiter, but the two satellites are very different. Europa has a smooth, icy surface with very limited vertical relief and few impact craters, though one of these, Pwyll, shows vivid rays extending outward and crossing all other features. In that location are plains, chaotic areas, and low ridges, together with shallow pits. Detailed views from space-craft (peculiarly Galileo) show what look remarkably similar icebergs, and it is widely believed that an sea of salty h2o lies below the visible surface, with the icebergs floating around ( Figure three). Fragmented blocks of ice seem to look very like the blocks in the Earth's polar seas during a springtime thaw.

Europa does not take a strong internal magnetic field, but information technology orbits within Jupiter'southward magnetosphere, and the instruments on Galileo have detected an induced magnetic field which produces significant furnishings linked with the rotational menstruation of the planet. Jupiter'south magnetic field at Europa changes direction every 5 $5 \frac{1}{2}$ h, and this indicates the existence of a layer of electrically conducting material, such as salty water, not far beneath the icy surface of Europa. Information technology seems that the body of water may lie at a depth of less than 100 km. If it really does exist (and every bit yet there is no final proof) in that location will be tidal effects. There have been the inevitable speculations almost possible life-forms, but conditions in such a strange, sunless sea would not appear to be inviting!

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Occupied and Empty Regions of the Infinite of Extremophile Parameters

Jeffrey M. Robinson , Jill A. Mikucki , in Habitability of the Universe Before Globe, 2018

iii.2 Europa: "World-similar" Subsurface Ocean

Europa is one of the four Galilean moons of Jupiter that gained significant astrobiological interest subsequently the Voyager one and two flybys and subsequent Galileo orbiter mission because of the likelihood of an ocean of liquid water beneath its surface. The moon'southward density indicates loftier water content, while a lack of cratering and the relative youthful surface features indicate geological activity driven by dynamic fluid processes below the chaff ( Fig. 4A ). Current models predict that tidal heating maintains enough heat to drive geothermal processes (Chyba & Phillips, 2007; Committee on Planetary & Lunar Exploration, 1999). Recently, agile cryovolcanism was observed at Europa (Nimmo & Pappalardo, 2016).

Two other Galilean moons, Ganymede and Callisto, are also likely to contain layers of subsurface liquid water; still, their orbits are farther abroad from Jupiter and experience less tidal heating, which is reflected in Callisto's ancient surface features. Modeling of Callisto and Ganymede besides indicates that layers of liquid h2o are likely present, simply probably not as close to the surface equally on Europa (Solomonidou et al., 2011; Schenk et al., 2004). Europa's bounding main is estimated to be 100–150 km deep or slightly deeper (168 km); the variation depending on the model and data used (Melosh et al., 2003; Pappalardo et al., 1998, 1999; Schubert et al., 2009). This is far deeper than the deepest betoken in World's sea; the lesser of the Mariana Trench is measured at x.99 km (Kato et al., 1998). The thickness of the ice crust and detailed understanding of the underlying layers remain unknown; estimates propose the ice crust ranges from ~ 1 to 30 km thick. On Earth, the Antarctic ice sheet is ~ 4 km at its thickest point and harbors active aquatic environments at its base, including the large Lake Vostok, which is most the size of Lake Ontario. A electric current hypothesis is that Europa has a difficult water ice shell that covers a warmer, convective "stratosphere" of water near its freezing signal or warm (i.e., slushy) ice (Fig. 4B). Significant heterogeneity betwixt regions is likely, for example, some of the nigh active geological features occur in locations where warmer brine from the interior bounding main may rise closer to the surface (Billings & Kattenhorn, 2005; Melosh et al., 2003; Ruiz, 1999; Sonderlund et al., 2014). Measurements of electric current from the NASA Galileo mission magnetometer indicated well-nigh-saturation salt content, while near-infrared assimilation spectra indicate high magnesium sulfate and sodium chloride content (Hand & Chyba, 2007; Zolotov & Shock, 2001). The brown coloration seen on Europa'due south surface (Fig. fourA) is interpreted equally irradiated salts from ocean water expunged during cryovolcanic activity (Hand & Carlson, 2015). Modeling of the interior thermodynamics and salinity suggests that plumes of geothermal heat would cook ice in dome-like formations reaching to v–xx km of the ice surface (Fig. fourC; Zolotov & Shock, 2004; Zolotov & Kargel, 2009).

The latest prove suggests that Europa's ocean is saline and contains various metabolic substrates, thus it may be the about Globe-like liquid ocean in the solar arrangement, providing a compelling astrobiological target. Continued exploration of Europa is in the planning and execution stages. The NASA Juno mission is currently in-orbit collecting data on the Jupiter system, while the European Space Bureau (ESA'due south) Jupiter Icy Moons Explorer (JUICE) is planned to orbit Ganymede and study subsurface liquid dynamics on Europa, Ganymede, and Callisto. NASA has besides proposed continuing Europa exploration that includes a lander and drilling mission (Europa Study Team, 2012).

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Possibility of Life on Other Planetary Bodies in Our Solar System

Akio Makishima , in Origins of the World, Moon, and Life, 2017

xi.4.3 Europa

Europa has a very different surface from its rocky neighbor, Io. A Galileo image of Fig. 11.8 hints at the possibility of liquid water beneath the icy crust of this moon. The bright white and bluish parts of Europa's surface are composed of h2o ice. In dissimilarity, the brownish regions on the right side of the prototype may be covered past salts (such as hydrated magnesium-sulfate) and an unknown red component. The yellowish terrain on the left side of the prototype is caused past some other unknown contaminant. This global view was obtained in 1997; the finest details that can exist discerned are 25 km across (Castillo-Rogez, 2015).

Indications of possible plume activeness were reported in 2013 by researchers using NASA's Hubble Infinite Telescope. NASA'south Hubble Space Telescope observed h2o vapor in a higher place the frigid due south polar region of Europa, providing the first strong show of h2o plumes erupting off the moon's surface.

Nonetheless, NASA'south Cassini spacecraft did non discover the plume action during its 2001 flyby of Jupiter. Either the feather activity was infrequent or the plumes are smaller than the plume on Enceladus (see Section 11.5.1).

Europa has become 1 of the most exciting destinations in the solar arrangement for future exploration because it shows stiff indications of having an bounding main beneath its icy crust; thus, there is a possibility of life.

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Cryovolcanism

Sarah A. Fagents , ... Tracy Grand.P. Gregg , in Planetary Volcanism across the Solar Organisation, 2022

Europa

Europa'southward extensively fractured, youthful surface was kickoff revealed by visits to the Jupiter system by the two NASA Voyager spacecraft in 1979, before being documented extensively past NASA'south Galileo mission between 1995 and 2003. The paucity of impact craters on Europa implies a surface age of merely 20–180 Ma (Schenk et al., 2004)––a geological blink of an eye––which in plow suggests that the trunk has been actively resurfacing throughout its history. Analyses of tidal stresses over Europa's surface indicate that any given location volition experience cycles of compressive, shear, and extensional stresses as the satellite travels around Jupiter in an eccentric orbit (Greenberg et al., 1998). Therefore, it might be expected that Europan fractures undergoing extension may open to expose water in a shallow ocean, and thus provide a pathway to the surface for vapor, sprays, or water from the subsurface. Indeed, explosive cryovolcanism is 1 of the numerous theories proposed for the formation of ridge systems flanked by night margins (e.m., Rhadamanthys Linea and other "triple bands": Fagents et al., 2000; Quick and Hedman, 2020).

The geologically young surface age and extensive fracturing have prompted a number of searches for agile plumes over the years, with mixed results. An early analysis of a single, depression-resolution Voyager 2 image indicated the possible presence of an active plume above Europa'southward vivid limb (Cook et al., 1983), only afterwards reexamination of the data concluded that the characteristic identified was an artifact of the vidicon image (Pappalardo et al., 1999; Phillips et al., 2000). Later, a careful search for surface changes over the 25-year timeline between the Voyager and Galileo missions led to no definitive detections of changes that might be attributable to explosive venting or some other cryovolcanic process (Phillips et al., 2000).

Similarly, a plume-search campaign during the Galileo mission, carried out under favorable illumination and stage bending conditions, as well failed to identify active plumes. On orbit "E17" of the mission, a series of images with a resolution of 72 m per pixel (m/pxl) was targeted forth the limb of Europa from ii°Due south to 15°N at 215°E longitude; 15 images were caused along the surface parallel to the limb and an additional 15 in the dark sky above the limb to search for diffuse glows in a higher place the surface or anomalously bright regions on the surface. No such features were identified, although Phillips et al. (2000) noted that the targeted search areas of the Europan surface were expected to be nether pinch at the fourth dimension of the observations. During orbits "G7" and "C20," images of Europa in eclipse were acquired to search for glowing "hotspots" of warm plume fabric above the disk of Europa. Although this technique worked well for identifying hot (> 1000 K) silicate volcanism on Io, a similar assessment of Europa again failed to identify whatsoever plumes. However, De La Fuente Marcos and Nissar (2002) reported Earth-based telescope observations of a transient brightening of Europa in 1999, interpreting their findings as possible prove of eruptive activeness.

It was not until recently that more than convincing evidence of agile plumes at Europa was institute, this fourth dimension with data acquired past the NASA/ESA Hubble Space Telescope. Using the Space Telescope Imaging Spectrometer (STIS), Roth et al. (2014) observed anomalous H and O emissions over a menstruum of vii hours in December 2012, which produced a feature extending above the surface of the south polar region (Fig. 13A ). Roth and coworkers interpreted these observations as a plumage of water vapor 200 km high, erupting at 500–700 g southward⁻¹. However, no other plumes were detected in similar images from 1999, or in 19 other observations between 2012 and 2015 (Rhoden et al., 2015).

Using an independent technique, Sparks et al. (2016) examined images of Europa in transit across the face up of Jupiter; processing the data to remove the contribution to the scene of Jupiter's disk revealed a feature interpreted to be a feather > 100 km high higher up Europa'southward limb in 4 of 12 transit images (Fig. xiiiB). Repeat observations revealed a 50 km-tall plume in one of the aforementioned locations as described in the previous study (Sparks et al., 2017). A recent reanalysis of Galileo magnetometer and Plasma Moving ridge Spectrometer information acquired during the spacecraft's closest encounter with Europa identified an anomaly in magnetic field and plasma wave density, which is consistent with the presence of a plume erupting from a location shut to the equator (Jia et al., 2018). Even so, analysis of Galileo Photopolarimeter Radiometer measurements of surface thermal backdrop showed no evidence for hotspot sources of potential plumes during the Galileo flybys (Rathbun and Spencer, 2020).

Nosotros can conclude from these investigations that, should these features indeed be eruptive plumes, they correspond exceptional, transient action, quite different from Enceladus' continuous output. Indeed, Paganini et al. (2019) suggested that large-scale plumes initially imaged past HST are outliers and that Europa'south plumage activity may be smaller in scale and desultory in nature, and hence difficult to identify with Earth-based techniques. Calculations of cavalcade density and total mass in the observed Europan plumes are greater than those on Enceladus (~ 10¹⁷ cm⁻² versus 10¹⁶ cm⁻² and ~ 10⁶ kg versus 10⁴ kg; Hansen et al., 2006, 2020; Roth et al., 2014; Sparks et al., 2016), and higher eruption velocities are required for a plume to reach a given height on Europa because of its higher gravity (ane.31 m s^−two versus 0.113 chiliad s⁻ⁱⁱ). One might speculate that these differences in plumage properties reflect unlike manifestations of tidal energy and responses to imposed stresses, or differences in subsurface plumbing, and perhaps in body of water composition, volatile content, and temperature.

Although it is not possible to construct detailed models of Europan plume eruptions without further observations to both confirm their beingness and characterize them more fully, we can speculate that the exposure of water at the surface of Europa would produce a spray of droplets and vapor equally water boiled into about-vacuum conditions, mayhap aided by exsolution of dissolved gases. This beliefs could be the case both for effusion of fluid on to the surface and for the exposure of a water column in a fracture. Although Roth et al. (2014) and Sparks et al. (2016) identified the estimate areas on Europa's surface that seem to serve as a source for the plumes, information technology was not possible to link those plumes to specific vents or cryovolcanic features imaged past earlier missions to Europa. The youth and complication of this satellite's terrain leaves open up the possibility that any number of surface features might act as a cryovolcanic source. For example, Fig. 13C–E shows prominent lineaments with night, diffuse margins, which are widespread on Europa. The deposition of cryoclastic material that erupted from a medial fracture is one origin suggested for these deposits, although thermally produced lag deposits of dark, non-H₂O solids is another possible origin (Fagents, 2003). Liquids exposed at Europa'due south chaos and lenticulae might likewise correspond to the sources for plumes.

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Extraterrestrial systems

S.K. Haldar , in Introduction to Mineralogy and Petrology (2d Edition), 2020

2.4.5.1 Europa

The Europa is the Jupiter'southward moon, originated 4.503 Ga agone, discovered on Jan 10, 1610, by Galileo Galilei and Simon Marius. The moon Europa is the smallest of the four large Galilean natural satellite orbiting the Blood-red Planet in a period of 85 h, or 3 and a half Earth-days. It is the sixth closest moon to the plant amid the 79 known moons. The distance to Globe is 628.3 1000000 kilometers (390.iv meg miles). The radius is ane,560.eight km (969.84 miles), making it smaller than the Earth'southward Moon, just larger than the Dwarf Planet Pluto. The mural presents a variety of colorful terrain with express groves, ridges, and mountains. Impact craters are visible on the surface.

The internal structure of Europa has been conceived as having a bulk composition of the rock–atomic number 26 core (Kuskov and Kronrod, 2005a,b). It is surrounded by a rocky mantle, and a geophysically and geochemically permissible 15–25 km thick outer shell composed predominantly ice floating on an sea lx–150 km deep. The surface of Europa is the brightest of the Galilean moons. The brightness and color of the surface are not uniform due to impurities of salts and silicates erupted from the interior-like volcanics or derived from exterior sources similar meteorites. The overall density of Europa is 3.00 g/cm³. Europa has a very thin atmosphere equanimous primarily of oxygen.

The possibility of the big potential of bounding main water, along with tidal heating in the rocky interior, Europa can exist considered one of the possible potential sources for extraterrestrial life in the Solar System in the body of water deep beneath the icy crust.

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Source: https://www.sciencedirect.com/topics/earth-and-planetary-sciences/europa

what appears to have caused the extensive cracking and streaking of the surface of europa?

Europa

3.3 Tidal Heating

Europa

3.3 Tidal Heating

Astrobiology

Europa

Astrobiology

6.four.one Europa

Astrobiology

half dozen.iv.1 EUROPA

SOLAR SYSTEM | Jupiter, Saturn and Their Moons

Europa

Occupied and Empty Regions of the Infinite of Extremophile Parameters

iii.2 Europa: "World-similar" Subsurface Ocean

Possibility of Life on Other Planetary Bodies in Our Solar System

xi.4.3 Europa

Cryovolcanism

Europa

Extraterrestrial systems

2.4.5.1 Europa

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