Space.com - 27 May 2010
There may be enough oxygen in the waters of Jupiter's moon Europa to support millions of tons worth of fish, according to a new study. And while nobody is suggesting there might actually be fish on Europa, this finding suggests the Jovian satellite could be capable of supporting the kinds of life familiar to us here on Earth, if only in microbial form.
Europa, which is roughly the size of Earth's moon, is enveloped by a global ocean about 100 miles deep (160 km), with an icy crust that may be only a few miles thick. From what we know of Earth, where there is water, there is a chance at life, so for many years scientists have speculated that this Jovian moon could support extraterrestrials.
As we learned more about Jupiter's effect on its moons, the possibility for life on Europa grew even more likely. Studies showed the moon could have enough oxygen to support the kind of life we are most familiar with on Earth.
The ice on the surface, like all water, is made from hydrogen and oxygen, and the constant stream of radiation pouring in from Jupiter reacts with this ice to form free oxygen and other oxidants such as hydrogen peroxide. The reactivity of oxygen is key to generating the energy that helped multi-cellular life flourish on our planet.
A model of Europa's interior, including a global ocean. If a 100 kilometer-deep ocean existed below Europa's ice shell, it would be 10 times deeper than any ocean on Earth and would contain twice as much water as Earth's oceans and rivers combined. Credit: NASA/JPL