Astronomers find evidence that Saturn’s moon Mimas hides a global ocean
Developing stronger arguments for the presence of water could help scientists better understand where to look for habitable worlds in deep space. Now they have found new evidence that one of Saturn’s smallest moons, Mimas, hides a global ocean beneath its icy surface.
Mimas was thought to be just a big chunk of ice, but data from NASA’s Cassini mission has changed that. The largest crater on Mimas is about 130 kilometers wide, which makes the moon look like the Death Star from “Star Wars” movie saga.
After analyzing orbital motion data, a team of European researchers has found that Mimas’ spin and orbital motion did not match if it had a pancake-shaped rocky core. Instead, they say that these movements suggest that Mimas has an internal ocean that has shaped its motion.
The researchers have determined that the ocean is relatively young, estimated to be only between 5 million and 15 million years old. They believe that the ocean, that is between 20 and 30 kilometers deep beneath the moon’s ice sheet, is evolving. The study could change the way astronomers think about moons in our solar system, and it may be time to look at other quiet moons that could be hiding conditions that can support life.
This discovery adds Mimas to an exclusive club of moons with internal oceans, including Enceladus and Europa. The findings could motivate comprehensive examinations of medium-sized icy moons throughout the solar system. One thing is for certain: this discovery has established the strongest evidence that Mimas actually has an ocean today.