Europa’s potential for diverse extraterrestrial ecosystems

Although some scientists are pessimistic about finding life elsewhere in our galaxy, there are many who believe our galaxy has many potential places in which life could exist. And some of Jupiter and Saturn’s moons are among the most promising.

Two proposed models of the subsurface structure of Europa. (Credit: NASA/JPL)

Kevin Peter Hand, a planetary scientist and astrobiologist, recently explained in an article published on CNN.com, “These moons — worlds with names like Europa, Enceladus, and Titan — are covered with solid water ice, beneath which we have very good reason to believe that vast liquid water oceans exist.” On Earth, where there is water, life is usually present. Hand surmises that these moons with substantial water “could be great homes for alien ecosystems.” But in saying this, he carefully notes, “When I say ‘alien ecosystems’ I’m referring primarily to microbes and simple life forms. As much as I’d love to discover creatures like those seen in the movie The Abyss, I’ll be happy just to find a considerable speck of a microbe!”

Hand believes Jupiter’s moon Europa may have the perfect combination of liquid water and the chemistry needed to sustain life. He describes, “Europa provides an incredibly compelling place to go to search for a second, independent origin of life and it’s a place where we might find lifeforms that are alive now, today.” As someone who has explored the deepest depths of Earth’s oceans, Hand knows very well that our understanding of habitable environments here on Earth continues to change with discoveries of ecosystems in the deepest parts of our oceans, and so too does our understanding of potentially habitable environments beyond Earth.

And with two-to-three times the volume of all the liquid water on Earth, Europa’s ocean is likely to have a wide variety of ecosystems.