Saturn’s moon Enceladus has geysers and a liquid ocean, and new simulations show that the liquid in the geysers may not come from that ocean. And that annoying reality means looking for life is harder than we thought.

Backing up. In 2005, the Cassini space probe was able to both image and measure geysers of ice coming from the surface of Enceladus. Early explanations leaned toward the geysers being triggered by quakes in the ice that released water from pockets between the surface and the sea. Later measurements, however, found they are salty water, and early modelers thought any salts from near-surface pockets should just leave the salt on Enceladus’s surface. That led to a new thought that the geysers could be expelling liquid all the way from a deep-down sea — a sea with possible life that could be easily sampled.

But physicist Colin Meyer looked to our own oceans for inspiration and realized that meltwater pockets could concentrate salts, creating a mix that could send salt to altitudes seen in Cassini’s measurements. Computer simulations proved this out and crushed a lot of hopes. Instead of Enceladus spewing water that may have circulated with deep-sea life, it is just tossing out fluid trapped in its icy skin.

Basically, Enceladus may still have subsurface seas, those seas may have life, and all of that may be out of our easy reach. Or — and this is now a less likely looking or — Enceladus may have geysers expelling liquid from that subsurface sea allowing us to sample any potential life. And not knowing which is the case, makes planning to go checking for life less straightforward than one might wish.

We are able to advance astronomy as we acquire more data, evolve the technology used to model that data, and realize what previously omitted physics really needs to be added into our estimations.

More Information

Enceladus’ plumes might not come from an underground ocean (Science News)