Water on Jupiter's moon!

The presence of water beyond Earth is Jupiter's moon Europa’s frozen surface is covered with distinctive pairs of ridges that straddle troughs of ice. These double ridges are the most common features on Europa. But scientists don’t yet have a clear idea of how these are created.

Now, an analysis of images of a similar set of ridges on Greenland’s ice sheet suggests that relatively shallow water within Europa’s thick icy shell may be behind their formation, scientists reported on April 19 in Nature Communications. This, if true, could mean that Europa has much more shallow liquid water than scientists have thought.

Europa’s double ridge systems, which can stretch for hundreds of kilometres, include some of the oldest features on the moon, says Riley Culberg, a geophysicist at Stanford University. Some researchers have proposed that the flexing of the moon’s icy shell due to tides in an underlying liquid water ocean plays a role in the ridges’ formation. Yet others have suggested that water erupted from deep within the icy moon — a process known as cryovolcanism — to create the ridges. Without a closer look, though, it’s been hard to nail down a more solid explanation.

Science News