Enceladus is one of the main interior satellites of Saturn and orbits within the densest part of the E ring, the outermost part of the rings of this planet. Its characteristics have made this moon an object of astronomical research for years. Now, the Cassini-Huygens probe has discovered that under the icy crust of Enceladus lurks a global ocean of liquid water . The finding has been published by NASA itself and the magazine Icarus .
Previous studies of the Cassini data had suggested the presence of a lens-shaped body of water or sea beneath the surface . Following the recent gravity data received by the spacecraft, the possibility arose that this presence of the sea could be global. The latest data analyzed by scientists confirm that this is the case: Enceladus contains a huge reservoir of liquid water.
“This was a difficult problem that required years of observations and calculations with a diverse collection of disciplines, but we are confident that we finally got it right, ” says Peter Thomas, study leader.
To reach this conclusion, the researchers completed more than seven years of Cassini-sent images of the moon Enceladus (which has been orbiting Saturn since 2004). By studying the positions of some unique features of the satellite such as its craters, they managed to make measurements of the changes of rotation of Enceladus with the closest possible precision, discovering a slight -but perceptible- wobble in its orbit around Saturn .
Measuring this slight oscillation (called libration) they raised different possible models of the interior of Enceladus, reaching the final result: “If the surface and the core were rigidly connected, the core would provide so much dead weight that the wobble would be much less. This shows that there must be a global layer of liquid that separates the surface of the nucleus ”, explains Matthew Tiscareno, co-author of the study.
The reason why this internal ocean is not frozen and remains in its liquid state, is still part of the mysteries of our universe yet to be solved.
