Acidic Europa May Eat Away at Chances for Life

The ocean underneath the icy shell of Jupiter's moon Europa could be too acid to support life, due to compounds that may regularly migrate downward from its surface, researchers find.

Europa, which is roughly the size of Earth's moon, could possess an ocean about 100 miles deep (160 kilometers). This ocean is overlain by an icy crust of unknown thickness, although some estimates are that it could be only a few miles thick.

Since there is life virtually wherever there is liquid water on Earth, for many years scientists have entertained the notion that this Jovian moon could support extraterrestrials. Recent findings even suggest its ocean could be loaded with oxygen, enough to support millions of tons worth of marine life like the kinds that exist on Earth. Researchers have proposed missions to penetrate Europa's outer shell to look for life in its ocean, although others have suggested that fossils of marine life on Europa could be available right on the surface for prospectors to find, given how water apparently regularly gets pushed up from below.

However, chemicals found on the surface of Europa might jeopardize any chances of life evolving there, scientists find. The resulting level of acidity in its ocean "is probably not friendly to life — it ends up messing with things like membrane development, and it could be hard building the large-scale organic polymers," said researcher Matthew Pasek, an astrobiologist at the University of South Florida.