There are actually a lot of places in the solar system where we might find life, and among all of them, Europa may be one of the most promising ones. Europa is one of Jupiter’s moons, and it has liquid water oceans hidden under its ice surface.  But be careful!

This surface is not thin as you might think: it is actually really thick, something like 20 km thick! One of the possible issues with this kind of surface, anyway, is that it might have not enough oxygen in order to host life. In fact, usually, oxygen tends to accumulate on the surface and we don’t know how it could reach the ocean underneath the thick layer.

So it could also be that this ocean of liquid water is a potentially habitable ocean, but with no oxygen reaching, that would basically be a waste of potential.

Of course, some forms of life could exist living without any oxygen, but it is really unlikely, or better said: the oxygen presence would give us a better chance to find aliens. So the question is: is there oxygen on Europa?

We still don’t know, and we will need more missions to understand it, but recently some studies suggested that we might have found a reasonable mechanism for the oxygen to reach the liquid ocean.