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NASA scientists have confirmed that Enceladus, the sixth moon of Saturn, is encircled by a vast liquid ocean. This has significant implications for our ongoing evaluation of where life is most likely to exist in the solar system. Enceladus has been thought to harbor significant subsurface oceans ever since the Cassini probe observed water-rich cryovolcano eruptions at the moon’s south pole. Research revealed that there are more than 100 of these plumes active at Enceladus’ south pole and that they collectively provide most of the material in Saturn’s “E” ring.

By 2014, NASA was certain that Enceladus had at least a large ocean at the south pole, but has since refined this further. By carefully measuring Enceladus’ wobble, the researchers determined that the moon’s orbital mechanics are only explained if its core is completely decoupled from its icy crust. If the entire moon was solid, the wobble would be much smaller and the observed deviations would not exist.

Enceladus’ cryovolcanos

Further investigations by Cassini have demonstrated that the south polar region of Enceladus is covered in heavily deformed surface ice, some of which may be as young as 1000 years. Unlike the rest of the planetoid, which is heavily cratered, the south pole shows very little cratering, suggested its topography was reshaped in the very recent past. The wobbles in the moon’s orbit, meanwhile, mean that the subsurface ocean is still liquid, not solid — and that means life could theoretically exist in the ocean of the little moon.

Unlike many of the other moons in our solar system, Enceladus’ core is thought to still be active. While this wasn’t always the case — early observers thought Enceladus was composed entirely of water ice — the moon is more dense than other Saturn satellites of similar size and is believed to contain a significant amount of radioactive isotopes. These, combined with Saturn’s gravitational influence, must have kept the core of the planet hot enough to remain molten, and therefore warm enough to melt the subsurface ocean.

The water on Enceladus might sustain life, but it’s nothing you’d ever want to drink. With an estimated pH value of 11-12, which puts above ammonia, but below mealtime staples like bleach, oven cleaner, or lye. All the same, there are extremophiles (so-called alkaliphiles) that are known to exist on Earth in environments where the pH is 8.5-11. Earth life has difficulty surviving in waters at a pH above 11, but life that evolved in such conditions might find them more hospitable.

Read more http://www.extremetech.com/extreme/214403-vast-liquid-ocean-encircles-enceladus-saturns-sixth-moon