Saturn’s moon could have hidden young ocean

(MENAFN) New research suggests that Mimas, Saturn’s small and heavily cratered moon, may harbor a subsurface ocean, potentially redefining how scientists classify ocean worlds in the solar system.

“When we look at Mimas, we don’t see any of the things that we’re accustomed to seeing in an ocean world,” Alyssa Rhoden, a planetary scientist at the Southwest Research Institute (SwRI), said at a recent planetary science conference, according to reports.

Despite its seemingly solid, cratered exterior, thermal and orbital modeling now indicates that liquid water could exist beneath 12 to 19 miles (20 to 30 kilometers) of ice. Initial hints of this possibility came from data collected by NASA’s Cassini spacecraft, but updated simulations provide stronger evidence for an internal ocean.

Rhoden’s team proposed that shifts in Mimas’ orbit likely generated internal heating through gravitational “tides,” which may have melted parts of the ice shell within the last 10 to 15 million years—a very short period in geological terms. “It would be hard, but may be doable,” Rhoden said about the challenge of detecting this hidden ocean with a future spacecraft.

In parallel, Rhoden’s colleague Adeene Denton examined Herschel Crater, Mimas’ most prominent feature, to better understand the moon’s geological history. “Mimas needs to be right on the tipping point,” Denton said, according to reports. Her research, published in Earth and Planetary Science Letters, indicates that the crater likely formed as the subsurface ice began to soften but had not yet fully melted.

Taken together, these studies suggest that Mimas, long thought to be a frozen and inert moon, may in fact host a young and active subsurface ocean. As Denton summarized, “All of these things are now building a coherent narrative about Mimas as a young ocean world.”

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