When it comes to the search for life in our solar system, Mars is not the only place of interest. Increasingly scientists are gazing upon Jupiter’s fourth biggest moon with hopeful eyes.
An icy moon, the surface is far too smooth for a body that is being bombarded by comet and meteorite impacts. This smoothness suggests that liquid water exists insulated below a frozen ice crust, and upon impacts can rise to the surface and fill in the craters. In fact, Europa’s global ocean contains about twice the amount of water as the oceans on Earth, and water is a key ingredient to look for if you want to find life as we understand it.
However it is not just water that life needs, but oxygen. With Europa’s oceans trapped beneath several miles of ice, it is cut off from the oxygen produced at the surface by the interaction of energetic cosmic rays and the water ice.
Scientists now think that this constant rising, surfacing and coating of the crust by liquid water allows plenty of oxygen to pass into the oceans.
And if there is water, and oxygen, then life could exist, even if it will likely be in the form of simple organisms living around hypothetical thermal vents at the bottom of its vast ocean.
Answered by Sophie Allan from the National Space Centre
Image courtesy of NASA/JPL/Ted Stryk