So, Europa is awesome. One of Jupiter’s moons, Europa is a really interesting place. Firstly because it has an atmosphere made up of oxygen, secondly because although the surface is a solid sheet of ice,it probably has a huge ocean made of liquid water underneath the layer of ice, and thirdly, it is one of the best candidates for alien life in our solar system.
The subsurface ocean
Scientists think that Europa has a layer of liquid water underneath its outer icy surface. While the surface is frozen, the water can remain liquid underneath because of something called “tidal flexing”. This is due to Europa’s orbit around the giant and very dense Jupiter - gravitational pull from Jupiter, and another moon Io, keeps the interior water moving about, creating enough energy to keep it warm and in a liquid state. And the ocean is huge - estimates put the volume of the ocean at about twice that of Earth’s ocean.
Warm, liquid, moving water is a good place for life to start up. But if the water is sterile, no amount of sloshing around will produce life. However, just recently more evidence for the moon being a good place for life has emerged. The surface was just found to have salt
on it, which indicates a possible ocean of sodium chloride - yep - that’s salt water just like in our own oceans on Earth! And very recent research also suggests that hydrogen peroxide
- an important energy supply that could be used to support life - exists on the surface of Europa as well. If the hydrogen peroxide is also in the oceans, this would provide a great way for life to start up, if it hasn’t already. Research done in the 1970s found that life doesn’t need sunlight to develop - using chemosynthesis, life is able to exist at the very depths of our own oceans, using thermal vents to produce their own food-cycle which doesn’t require any photosynthesis at all. So life could very well use a similar mechanism to develop and survive in pitch-black water underneath the icy exterior of Europa as well. Ships and robotic probes that are scheduled for Europa in the ’20s and ’30s will be able to tell us a lot
more. I can’t wait!