Hidden Ocean Beneath Saturn’s Moon Mimas Reveals a Surprising Origin Story


In a remarkable revelation, scientists have uncovered a well-hidden secret beneath the pockmarked surface of Mimas, one of Saturn’s smallest moons – a vast global ocean of liquid water. Led by Dr. Valéry Lainey from the Observatoire de Paris-PSL, the discovery, published in the journal Nature, suggests that Mimas is home to a relatively “young” ocean, formed a mere 5 to 15 million years ago. This discovery positions Mimas as a crucial celestial body for unraveling the mysteries surrounding the origins of life within our Solar System.

Mimas, measuring a modest 400 kilometers in diameter, initially betrayed no indications of the concealed ocean beneath its heavily cratered exterior. Dr. Nick Cooper, co-author of the study and Honorary Research Fellow at Queen Mary University of London, notes, “Mimas adds to an exclusive club of moons with internal oceans, such as Enceladus and Europa, but with a unique twist: its ocean is remarkably young.”

The youthfulness of Mimas’s ocean, discerned through a meticulous analysis of its tidal interactions with Saturn, implies its relatively recent formation. The unexpected irregularity in Mimas’s orbit allowed scientists to estimate the ocean’s age, offering a distinctive insight into the early phases of ocean formation and the potential for life to emerge.

“This discovery positions Mimas as an ideal candidate for researchers delving into the origin of life,” states Dr. Cooper, emphasizing the significance of the recently formed liquid water ocean on Mimas.

The groundbreaking findings were made possible by scrutinizing data collected by NASA’s Cassini spacecraft over a decade of studying Saturn and its moons. The researchers closely examined subtle changes in Mimas’s orbit, unveiling the presence of the hidden ocean and enabling estimates of its size and depth.

Dr. Cooper underscores the collaborative effort involved in the discovery: “This has been a great team effort, with colleagues from five different institutions and three different countries coming together under the leadership of Dr. Valéry Lainey to unlock another fascinating and unexpected feature of the Saturn system, using data from the Cassini mission.”

Beyond its scientific significance, the revelation of Mimas’s young ocean has profound implications for understanding the potential for life beyond Earth. The study suggests that seemingly inactive moons, even smaller in size, can harbor hidden oceans capable of sustaining conditions essential for life. This discovery paves the way for future exploration and raises exciting prospects in the quest to answer the age-old question: are we alone in the universe?