Saturn's wobbly moon is home to an ocean that could be life-friendly

Scientists have found that below the crust of one of Saturn’s moons, Enceladus, is a layer of liquid oceans that covers the moon’s entire surface. That ocean could be home to extraterrestrial life.

Researchers looked at detailed images of Enceladus captured by NASA’s Cassini mission, which has been circling the planet for more than a decade. Analysis of years-worth of images showed that Enceladus’ rotation is slightly wobbly, and computer modeling suggests that wobble comes from an underground ocean. Cassini’s Matthew Tiscareno explained in a statement, “If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be… This proves that there must be a global layer of liquid separating the surface from the core.”

The findings, co-written by Tiscareno, lead author Peter Thomans and others, were published in the journal Icarus.

Enceladus has long been a source of interest for NASA. In 2005, scientists first saw plumes of water vapor emerging from the moon’s surface. Later, researchers speculated on whether it could be coming from an underground lake. Last year, scientists concluded that Enceladus harbored an ocean beneath its surface, but didn’t think it extended across the entire moon.

Enceladus’ ocean is a very good candidate for fostering life. A previous study suggested that Enceladus’ ocean has hydrothermal vents. That’s a big deal, according an author of that study, Hsiang-Wen Sean Hsu. He told Space.com, “Hydrothermal systems could fulfill the three criteria to sustain life: energy, nutrients and liquid water.” Hsu added, “There is no guarantee… but the chances to find life are surely much better with active hydrothermal systems.”

We’ll take those odds.

Danielle Wiener-Bronner is a news reporter.