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Scientists have stated that Saturn’s “Death Star” moon, with its icy and cratered surface, could potentially hide a surprisingly young ocean. This makes it an ideal location to study the beginnings of life.
Astronomers theorize that liquid water emerged on Mimas, the smallest and closest moon to the planet, approximately five to 15 million years ago. This discovery suggests that Mimas is significantly younger than Earth’s oceans, which are estimated to be over four billion years old.
Mimas is frequently likened to the Death Star of Star Wars fame due to its expansive Herschel Crater, which bears a striking resemblance to the hollowed-out design of the imaginary space station’s powerful laser cannon.
However, without any indications of activity, this tiny moon, measuring approximately 400 kilometers in diameter, would have been the least likely location to contain a global ocean beneath its surface.
Despite initial assumptions, scientists have found evidence that Mimas may possess a subterranean ocean situated only 20-30km beneath its frozen exterior.
This satellite is part of a group of satellites that are thought to have oceans below their surfaces, including Europa and Ganymede of Jupiter, and Titan and Enceladus of Saturn.
According to Dr. Nick Cooper, an honorary research fellow at Queen Mary University of London, Mimas is a relatively small moon with a diameter of approximately 400 kilometers. Despite its heavily cratered surface, there were no indications of the concealed ocean that lay beneath its surface.
“This finding includes Mimas in a select group of moons that have internal seas, such as Enceladus and Europa. However, it stands out due to its distinct feature: its ocean is relatively young, believed to be between five and 15 million years old.”
He commented that the discovery of a newly formed ocean on Mimas makes it an ideal subject for further research on the origins of life.
A team led by Dr. Valery Lainey from the Paris Observatory in France analyzed data from Nasa’s Cassini spacecraft for a study published in the journal Nature.
Cassini spent over ten years studying Saturn and its moons before ultimately crashing into the planet in 2017.
The scientists were able to determine the size and depth of a hidden ocean on Mimas by carefully analyzing the small changes in its orbit.
The scientists stated that these discoveries have also enabled them to dismiss the idea of a solid center within Mimas, stating that the presence of extensive inner oceans “is the only explanation that aligns with the data.”
The team’s findings suggest that even small and seemingly inactive moons may contain hidden oceans that could support the necessary conditions for the creation of life.
Matija Cuk from the SETI Institute in California and Alyssa Rose Rhoden from the Southwest Research Institute in Boulder, US, wrote in Nature’s News and Views that the concept of small, icy moons containing youthful oceans is intriguing. They also noted the potential for significant changes to have taken place in these moons’ recent past.
The discoveries of Lainey and her team will inspire a comprehensive investigation of medium-sized frozen moons across the Solar System.