NASA: Europa is strongly believed to hide a deep ocean of salty liquid water beneath its icy shell. by Preston Dyches via Jet Propulsion Laboratory
'Whether the Jovian moon has the raw materials and chemical energy in the right proportions to support biology is a topic of intense scientific interest. The answer may hinge on whether Europa has environments where chemicals are matched in the right proportions to power biological processes. Life on Earth exploits such niches.
'In a new study, scientists at NASA's Jet Propulsion Laboratory, Pasadena, California, compared Europa's potential for producing hydrogen and oxygen with that of Earth, through processes that do not directly involve volcanism. The balance of these two elements is a key indicator of the energy available for life. The study found that the amounts would be comparable in scale; on both worlds, oxygen production is about 10 times higher than hydrogen production.
'The work draws attention to the ways that Europa's rocky interior may be much more complex and possibly earthlike than people typically think, according to Steve Vance, a planetary scientist at JPL and lead author of the study. "We're studying an alien ocean using methods developed to understand the movement of energy and nutrients in Earth's own systems. The cycling of oxygen and hydrogen in Europa's ocean will be a major driver for Europa's ocean chemistry and any life there, just as it is on Earth."'