It may seem plain at a first glance, but Saturn’s moon Dione may once have a geologically active subsurface ocean, as revealed by new images from NASA's Cassini spacecraft.
The photos from the Janiculum Dorsa, a 500-mile long mountain, suggests that the moon may have had been a fragile imitation of Saturn’s icy geyser moon Enceladus.
According to Bonnie Buratti, who leads the Cassini science team at NASA's Jet Propulsion Laboratory in Pasadena, California, there is a possibility that there might be more worlds out in space with water than what was previously considered.
Previously, subsurface oceans were only thought to have existed on more than a few bodies in the solar system, that includes Jupiter’s moon Europa, and two of Saturn’s moon Titan and Enceladus. Such were considered geologic hotspots and have earned the curiosity of scientific communities who are looking for the building blocks of life beyond our home planet. If Dione would turn out to contain a liquid layer beneath the crust, this would increase the satellite’s chance for supporting life as well.
Using a magnetometer, Cassini, which has been investigating Saturn since 2004, was able to detect a weak particle stream coming from the moon. The photos taken by the spacecraft implies a spongy layer of liquid that could exist underneath the icy crust. Evidences of ancient and inactive fractures that now eject ice water and other particles containing carbon may have also existed, just like those seen in Enceladus.
The height of Dione’s Janiculum Dorsa runs from one to two kilometers in height, which is around 0.6 to 1.2 miles. It also seems like the mountain may have been deformed by the icy crust beneath the surface by as much as 0.5 kilometer or around 0.3 mile. According to the researchers, the deformation is evidence that the surface was once warm and more likely from a subsurface ocean when the mountain was formed.
