Plate tectonics on Jupiter's moon Europa could make finding life there more likely:
Earthquakes could be fueling life on Europa, one of Jupiter's moons. Scientists have shown that huge chunks of the moon's ice crust could be sinking others, infusing its underground ocean with chemical food. [...] Geophysicists from Brown University in Providence, Rhode Island, have shown that tectonic activity is also feasible within Europa's ice shell. They used a computer simulation to map subduction—where one giant slab of ice is forced under another.
The gravitational pull of moons could extend the unfrozen lifetime of subsurface oceans on some objects, such as Pluto and Charon:
Heat generated by the gravitational pull of moons formed from massive collisions could extend the lifetimes of liquid water oceans beneath the surface of large icy worlds in our outer solar system, according to new NASA research. This greatly expands the number of locations where extraterrestrial life might be found, since liquid water is necessary to support known forms of life and astronomers estimate there are dozens of these worlds.
"These objects need to be considered as potential reservoirs of water and life," said Prabal Saxena of NASA's Goddard Space Flight Center in Greenbelt, Maryland, lead author of the research published in Icarus [DOI: 10.1016/j.icarus.2017.11.023] [DX] November 24. "If our study is correct, we now may have more places in our solar system that possess some of the critical elements for extraterrestrial life."
List of largest lakes and seas in the Solar System.
Also at Brown University (EurekAlert).
Porosity and salt content determine if subduction can occur in Europa's ice shell (open, DOI: 10.1002/2017JE005370) (DX)
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Europa Lander May Not Have to Dig Deep to Find Signs of Life
If signs of life exist on Jupiter's icy moon Europa, they might not be as hard to find as scientists had thought, a new study reports. [...] NASA aims to hunt for such samples in the not-too-distant future. The agency is developing a flyby mission called Europa Clipper, which is scheduled to launch in the early 2020s. Clipper will study Europa up close during dozens of flybys, some of which might be able to zoom through the moon's suspected water-vapor plumes. And NASA is also working on a possible post-Clipper lander mission that would search for evidence of life at or near the Europan surface.
It's unclear, however, just how deep a Europa lander would need to dig to have a chance of finding anything. That's because Europa orbits within Jupiter's radiation belts and is bombarded by fast-moving charged particles, which can turn amino acids and other possible biosignatures into mush.
That's where the new study comes in. NASA scientist Tom Nordheim and his colleagues modeled Europa's radiation environment in detail, laying out just how bad things get from place to place. They then combined these results with data from laboratory experiments documenting how quickly various radiation doses carve up amino acids (a stand-in here for complex biomolecules in general).
The researchers found significant variation, with some Europan locales (equatorial regions) getting about 10 times the radiation pounding of others (middle and high latitudes). At the most benign spots, the team determined, a lander would likely have to dig just 0.4 inches (1 centimeter) or so into the ice to find recognizable amino acids. In the high-blast zones, the target depth would be on the order of 4 to 8 inches (10 to 20 cm). (This is not to imply that potential Europan organisms would still be alive at such depths, however; doses there are high enough to cook even the hardiest Earth microbes, study team members said.)
Also at Motherboard and Gizmodo.
Preservation of potential biosignatures in the shallow subsurface of Europa (DOI: 10.1038/s41550-018-0499-8) (DX)
Biosignature hide and seek (DOI: 10.1038/s41550-018-0542-9) (DX)
Europa volcanism & interior heating modeled in detail, offers research targets for upcoming missions
Europa, an icy Jovian moon that likely possesses an ocean beneath its icy crust, may have an interior that is hot enough to produce volcanic activity on its seafloor. New research provides evidence that this seafloor volcanism likely occurred in the moon's past and [may be] ongoing at present as well.
The team of researchers, led by Dr. Marie Běhounková of Charles University in the Czech Republic, developed their own 3D models of Europa's interior and heating transfer properties to investigate the possibility of volcanism on Europa's ocean floor given other volcanism seen in the Jovian system.
[...] These volcanoes would form due to the melting of Europa's interior and heat transfer from the rocky interior of Europa to the seafloor. Models developed by Běhounková et al. show that many different factors — including radiogenic power and tidal forces — contribute to the melting of the icy moon's interior.
[...] A Laplace resonance is a phenomenon that occurs when three planetary bodies with an orbital period ratio of 1:2:4 exert regular and periodic gravitational effects on each other. These nudges create tidal forces that translate to the heating of the body's interior.
It's that interaction that led Běhounková et al.'s research toward the conclusion that this resonance and the associate tidal forces can cause increased periods of volcanic activity — called magmatic pulses — on Europa.
Journal Reference:
Marie Běhounková, Gabriel Tobie, Gaël Choblet, et al. Tidally Induced Magmatic Pulses on the Oceanic Floor of Jupiter's Moon Europa, Geophysical Research Letters (DOI: 10.1029/2020GL090077)
Previously: Hydrogen Emitted by Enceladus, More Evidence of Plumes at Europa
Plate Tectonics on Europa and Subsurface Oceans in the Outer Solar System
NASA Finds Evidence of Water Plume on Europa
Europa Plume Sites Lack Expected Heat Signatures
Jupiter's Watery Moon, Europa, Is Covered in Table Salt
Jupiter's Ocean Moon Europa Probably Glows in the Dark
(Score: 2) by aristarchus on Sunday December 10 2017, @08:49AM
I am amazed that this fine Submission has garnered no comments. The existence of such surface dynamics should make the penetration of Europa much easier, once humans send a probe to this moon. Ice fishing on Europa, as Neil Degrasse-Tyson put it.