When we discussed the sub-surface oceans of some of the large moon-worlds, I was particularly excited about the idea that these places could potentially contain life, for what could be more exciting than the possibility of life elsewhere in the universe? As such, for my blog post, I wanted to dive into one potential home for alien life, Europa, and explore why it particularly is in contention for the possibility of having life.
One of the most significant aspects of Europa that make it tenable to life is that it has a salty, subsurface ocean. Scientists know this because we have detected a magnetic field coming from it, that could best be explained by such a feature beneath it’s thick ice crust. Moreover, the fact that the icy surface seems to be relatively unmarked in terms of cratering indicate that it is relatively active geologically, since lack of craters means the surface is caused to change often enough for craters to be infrequent. There are also scratches and strange features on its surface that are best explained by the shifting of ice, likely on a large body of water – that same subsurface ocean.
Just as importantly, scientists believe elements like carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur, all of which are essential to life’s formation, were likely on Europa when it formed, and asteroids might still be introducing new carbon now. Significantly, it’s thought that tidal forces – as indicated by the geological activity above – might be heating up part of Europa’s ice enough for it to melt off and provide nutrients, then new liquid becomes ice.
One final issue arises though: how could Europan lifeforms get energy? They could not get it from the sun as most earthly organisms ultimately do. They’d have to be in the pitch black ocean world beneath Europa’s ice! This point can be answered by the idea that there is likely a rocky interior beneath the subsurface ocean, and the tidal heating mentioned above causes this interior to have volcanic activity, spitting out heat and chemical reactions to potentially provide energy for life, albeit life somewhat different from how we know it. It is still, according to some scientists, distinctly possible!
All in all, it is distinctly possible for Europa to have life (albeit likely small, microbial life), and it would be a very unique sort of life that could reveal much about the origins and construction of life as we know it!
