Life on Enceladus?

For many years, scientists have wondered whether life could be possible or already occurring in other locations in the universe other than in Earth. One location that gets a lot of attention is Enceladus. Enceladus is one of the innermost moons of Saturn. The surface is covered in ice but underneath, there is liquid. This can easily been seen by the geyser activity that Enceladus has, spewing water into space. Since the moon is covered in ice, it reflects nearly all of the light from the son, making the surface temperature a frigid -201 degrees Celsius. The Cassini spacecraft also discovered an atmosphere originating from the moon's surface or interior. 

Enceladus and Saturn

But how does this have anything to do with life? Well there are places on Earth with ecosystems similar to that on Enceladus where life exists. There are three of these ecosystems, two that are for methanogens, a type of archaea that pull their energy from the chemical interaction between rocks. And the other one is where the energy is produced from radioactive decay in rocks. The first two are located in deep volcanic rocks along the Columbia River and in the Idaho Falls. The third can be found deep below the surface in a mines in South Africa.

Tau  Tona mine located in South Africa which goes down 3.9 km

Now we know the feasibility of life on Enceladus, since we have seen microbial lifeforms existing in such ecosystems. But how would have life started in the first place? There is two theories, the primordial soup theory and the deep sea vent theory. Both are reasonably easy to understand, but extremely hard to replicate in a lab setting. The primordial soup states that in a soup of organic material, the building blocks of life would form by themselves in the soup, and gradually life would be formed. An experiment was done in which a spark passed through chemicals thought to be present in early Earth, such as methane and ammonia, caused the formation of  few amino acids. These organic chemicals or available on Saturn's moons, making this theory extremely viable. 

Amino acids forming proteinoids

In the deep sea vent theory, chemically rich fluids are heated and emerge from the sea floor. The chemical energy is provided by the reduced gases such as hydrogen sulfide and hydrogen coming out of vents in contact with oxidants such as carbon dioxide. These little hot spots on the Enceladus sea floor could be little hubs of life formation. 

Hydrothermal vents that spew out hot chemicals into the surrounding environment

All these theories indicate the possibility of life on Enceladus, but until there is solid evidence, this hope for life on a distant moon can never be supported.