Scientists have revealed new evidence for tectonic activity on Jupiter’s moon Europa, which could supply food to life in the ocean below.
Published in the Journal of Geophysical Research: Planets, scientists from Brown University in Rhode Island used computer modeling to see if subduction was possible in Europa’s icy shell.
This is the process through which one tectonic plate slides underneath another. Earth is the only place we definitely know has tectonic activity, although Mercury looks like it might too.
This research suggests that Europa might also be such a world, something theorized before. It looked at how the process would take place on this icy world, and suggests that Europa’s icy shell could have two layers. One would be a thin outer layer of very cold ice, the other a slightly warmer layer of convecting ice.
If there are varying amounts of salt in the outer icy shell, then it might be possible for plates from the outer shell to submerge into the lower shell. Or, in other words, subduction.
On Europa, we can see regions where the icy shell looks to be expanding, similar to mid-ocean spreading ridges on Earth. However, we weren’t quite sure how the process would take place, something this research hopes to partially answer.
“We have this evidence of extension and spreading, so the question becomes where does that material go?” said Brandon Johnson, lead author of the study, in a statement.
“On Earth, the answer is subduction zones. What we show is that under reasonable assumptions for conditions on Europa, subduction could be happening there as well, which is really exciting.”
The research is particularly exciting because the surface crust is likely to be enriched with chemical food for life like oxidants. If plates are subducting, then this food could come into contact with the ocean below the icy surface.
“If indeed there’s life in that ocean, subduction offers a way to supply the nutrients it would need,” Johnson added in the statement.
“It’s fascinating to think that we might have plate tectonics somewhere other than Earth.”
There's still some way to go until we know what's going on for sure, but it's still pretty promising. In our hunt for life elsewhere Europa looks like a pretty good bet, and if it has plate tectonics, then any life in its ocean might just have a better chance of surviving.