In Arthur C. Clark’s novel, 2010, the story ends with a warning to humans ready to explore the Jovian moons: “All these worlds are yours — except Europa. Attempt no landings there.” In the next book, we learn that life has made a foothold on this icy-looking world.
Science fiction or science fact? It is possible that life could exist in water oceans beneath the thin ice crust of this little moon. Is it probable? We don’t know.
The Voyager and Galileo missions have mapped this world extensively, studying its icy surface. In the image shown here (taken by the Galileo spacecraft’s cameras), we see an area on Europa called the Conamara region. It is basically a frozen set of “ice rafts” created when large blocks of ice were disrupted during an impact. After the ripples from the crash died down, these “rafts” and criss-crossed cracks froze into place on the little moon’s surface. This event formed a crater Pwyll, which lies 1000 kilometers (640 miles) away.
Beneath this jumbled icy terrain lies an ocean of what is probably slushy ice water. At the core of this tiny world, there could be heat — generated by the continual and combined tidal pull of Jupiter on one side of Europa and the outer moons on the other side. If there IS heat at the center of this watery world, it’s possible that life could survive there. But, for now, we don’ t know if there are any Europan life forms colonizing these oceans. That discovery awaits future visits by robotic spacecraft, and eventually — human explorers.