NASA's Cassini spacecraft has discovered a subsurface ocean on Saturn's moon Dione. It was also instrumental in the same discovery on Saturn's other moons, Titan and Enceladus. Researchers from the Royal Observatory of Belgium have recently published their findings in the Geophysical Research Letters.
Dione's Subsurface Ocean
The Cassini spacecraft was able to provide gravity data from one of its flybys. The said data suggests that Dione's crust floats on an ocean located 100 kilometers below the surface. The study indicates that Dione actually has several tens of kilometers deep subsurface ocean. Apparently, it also surrounds a large rocky core.
The study's co-author Attilio Rivoldini explains that the connection between the rocky core and ocean is significant. The researchers revealed that the seemingly quiet nature of Dione is contrary to its actual past. It is not just evident on Dione's broken surface.
Apparently, the said ocean may be as old as the whole history of the moon. This means that it could have supported microbial life for some time. Rivoldini quite confirms this based on the possible interactions of the rock and water. It should provide nutrients and energy source that are needed in life's existence.
Saturn's Moon Dione, Enceladus and Jupiter's Europa
According to Astronomy Now, Dione is the lesser known moon of Saturn. It looks similar to Enceladus but Dione is only bigger. However, it does not spurt water vapor into space like Enceladus and Jupiter's moon Europa.
This is may be caused by Dione's deeper subsurface ocean, which is located between the moon's crust and core. Antony Trinh, a co-author of the study, disclosed that Cassini was not able to detect Dione's libration, though they say that an orbiter will be launched to test their prediction.
The Cassini spacecraft is nearing the end of its mission. It is set to crash into Saturn on Sept. 15, 2017.
