NASA: Life Could Exist on Saturn's "Ocean Moon" Enceladus

And Jupiter's Luna-sized moon Europe too.

The moons are "ocean worlds." They're covered in ice, but there are frequent "plumes" of presumably hot steam jetting up out from between the cracks in the ice -- more plumes coming from Saturn's Enceladus than Jupiter's Europa.

They've detected molecular hydrogen (H2) in Encedalus' plumes, which is a potential source of energy for life forms (and is in fact used as food for some Earth bacteria).

They also notice there are almost no craters on Encedalus' icy face, which must mean there is enough motion going on underneath the ice to "subduct" plates of it under other plates, like the earth's rocky plates subduct under others. This once again suggests there's a fair amount of heat underneath the ice.

Heat plus food suggests the potential for alien life.

Where's the warmth for these oceans coming from? From the tidal forces of the moons orbiting very large planets. The differential between the force of gravity on one side of the moon is different from the force on the other side, and that creates tensions and distortions in the moon, which is then released as heat.

With this analytical hurdle cleared, Waite and his team were able to calculate that H2 makes up between 0.4 percent and 1.4 percent of the volume of Enceladus' geyser plume. Further calculations revealed that carbon dioxide (CO2) makes up an additional 0.3 percent to 0.8 percent of the plume's volume. [Inside Enceladus, Icy Moon of Saturn (Infographic)]

The molecular hydrogen is most likely being produced continuously by reactions between hot water and rock in and around Enceladus' core, Waite and his colleagues concluded. They considered other possible explanations and found them wanting. For example, neither Enceladus' ocean nor its ice shell are viable long-term reservoirs for volatile H2, the authors wrote, and processes that disassociate H2 from water ice in the shell don't seem capable of generating the volume measured in the plume.

The hydrothermal explanation is also consistent with a 2016 study by another research group, which concluded that tiny silica grains detected by Cassini could have been produced only in hot water at significant depths.

Incidentally, molecular hydrogen is only found in lower quantities in earth's ocean, but only because it tends to be eaten up as a chemical food source by microbes.

Apparently Enceladus is where the real interest is right now, though they hold out some hope for Europa too.

Enceladus doing some venting
Photocredit: Me. I took this picture with my secret robot
satellite which I call Greg the Secret Robot

posted by Ace at 04:35 PM

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