Saturn's smallest satellite Mimas is knownreminiscent of the Death Star combat space station because of the characteristic crater on the surface. Astronomers said they were approaching a mystery that had troubled scientists for decades.
Scientists believe that unusual satellite vibrations,revolving around a planet caused by a weak core or underground ocean of water. Mimas sways twice as much as expected for a celestial body with a constant solid structure. This satellite of Saturn has a diameter of 396 kilometers and is mostly formed by ice.
Researchers have two explanations for the mysterious behavior of Mimas: either the moon has a huge subsurface ocean, or its core has an oblong shape, similar to a melon.
The study was published in a scientific journal.Science Magazine. The authors of the work are astronomers from the USA, France and Belgium, whose conclusions are based on high-quality photographs of Mimas provided by NASA's Cassini space probe. The device was sent to Saturn in 1997 in order to study the planet and its many satellites, the total number of which reaches 62 (some of them have no name).
After a thorough study of Mimas, we foundthat it liberates, that is, sways slightly when moving in orbit. Available data indicate that some unusual processes are taking place inside the moon, ”says lead author of the study, Radwan Tadjeddin of Cornell University (USA).
Interestingly, the surface dotted with cratersMimasa does not mean anything unusual by itself. Scientists connect the version with an oblong core with age-related changes in the moon - Mimas was formed more than four billion years ago. If there is an ocean under its surface, then Mimas will automatically join the oceanic worlds, among which several satellites of Jupiter and two other moons of Saturn - Enceladus and Titan.
Given the absence on the surface of Mimassigns of geological activity, the possible presence of an underground ocean there surprises researchers. Like most moons in the solar system, including ours, Mimas is always facing one of the parent planets. This is explained by such a phenomenon as spin-orbit resonance - synchronization of the orbital motion of a celestial body and its rotation around its axis.
Researchers hope to solve the mysteries of Mimas by further observing his vibrations. According to their estimates, the ocean of liquid water is at a depth of 24 to 31 kilometers from the surface.
Mimas is too small to maintain the innerheat - additional energy sources are required to maintain geological processes on the satellite. Researchers say they have evidence that in the past, Mimas had a more elongated orbit than now. Perhaps this provided a sufficient amount of tidal energy for the formation of the ocean.