Dec 13, 20244 min read

Could there be life on one of Jupiter’s moons–Europa?

Cailin Rugema

Side Photo of Saturn — Photo via *Unsplash.com*

Introduction

Besides the planet Earth we humans live on, the most researched and studied second base of life is Mars.

One of the pros is its relatively easy access for exploration compared to most planets because of its proximity to Earth. Another is the proven existence of liquid water that existed decades ago on Mars’ surface. Through these discoveries, many astrobiologists and specialists alike remark on the possibility of life being viable on Mars because where there is water there is life.

Europa

But what about life a little further? We’ve talked about what's on Mars, but what about one of Jupiter’s moons–Europa? This is the fourth largest out of the 95 moons that orbit around Jupiter and the sixth closest in the vicinity to Jupiter was

discovered in 1610 by Galileo. The frozen moon is about 380 million km away from planet Earth and holds temperatures as cold as -170℃ (260 F) causing it to have an icy shell. Other than the icy shell on the surface of the moon it is also primarily made out of silicate rock and possibly an iron-nickel core.

Potential Life on Europa

In the recent decade of research, there has been more emphasis on the exploration of this moon, this is due to the speculation of a possibility that Europa is capable of being able to carry life. Strong evidence has been shown by NASA that beneath Europa's frozen exterior of ice lies an ocean of liquid water, which is also one of the essential ingredients for all living organisms. Many scientists also agree that this vast subterranean sea could host multiple microorganisms similar to the proportions of bacteria found on Earth. While this claim has been contradicted by some stating that it would not be possible due to the lack of sunlight reaching the surface (due to the thickness of the ice layer) so processes like photosynthesis would be hindered, others say that alternative energy sources are possible for this moon.

According to Chyba, a likelier source of energy may come from fast-moving, charged particles that pound Europa from the atmosphere of Jupiter; the planet itself has the strongest magnetic field about 10 times that of Earth, which ties its effect to Europa due to its orbital path. The magnetic field causes ions to slam into the icy surface at high velocities, which may allow chemical reactions to likely occur, one being that frozen water molecules and carbon dioxide can transform into an organic compound such as formaldehyde, which can act as an energy source for a common bacteria on Earth known as Hyphomicrobium.

Europa's Big Challenge

One of the biggest challenges, however, isn’t the distance or the magnetic field radiation, but the ice sheet that hides the surface of the liquid ocean on this moon. It is said to be about 80 to 170 km thick (50 to 100 miles), if it is said that microorganisms can survive on this terrain, there has to be a way for these compounds to get through the dense layer of ice into the ocean. Thankfully a hopeful solution to this is the tidal heating faced on the moon, as Europa orbits Jupiter, the immense gravitational pull causes the moon to flex, this constant flexing generates heat through friction within the ice and the underlying rock, which may cause ice to thin out in certain areas. The heat from Europa's rocky mantle, combined with tidal stresses, may drive hydrothermal activity at the seafloor; this heat could transfer upward, thinning the ice or melting it in specific regions. There has been evidence of all of this occurring, where the presence of chaotic terrain (regions of broken and tilted ice blocks) suggested melting or partial liquefaction

beneath the surface.

Future Research at Europa

Moreover, while the rate at which the natural heating occurs on the surface may be slow-paced, and could take several decades for any major effect, with more research and experiments on the composition of the surface, more breakthroughs could come about. Especially when missions like the Europa Clipper by NASA are underway, this mission in particular was launched in October of 2024 and is expected to arrive in 2030. This mission’s main purpose will be to determine if life is possible on Europa, a series of experiments will be made namely to determine the thickness of Europa's icy shell, the moon's composition, to characterize Europa's geology and determine if there are places below the surface that could support life.

Conclusion

But let's think about what this could mean for us as a humanity. Not only would we have multiple breakthroughs in our understanding of biology and chemical processes or elements that occur on the moon, but could ultimately show that there could be multiple other astronomical objects capable of hosting life. The possibility of life on Europa challenges us to rethink the uniqueness of Earth as a cradle for life and expands our understanding of habitability in space. Discovering even the simplest organisms beneath its icy crust would affirm that life can be possible in diverse and extreme environments, which would inspire hope that the universe teems with living worlds.