Space & Astronomy

'Death Star' moon hides mystery interior

By T.K. Randall
October 17, 2014 ·  8 comments

Is there a hidden ocean underneath the surface of Mimas ? Image Credit: NASA A rocky and seemingly barren world, Mimas had up until now received relatively little in the way of attention compared to some of Saturn's better known moons such as Titan and Enceladus.

The turning point came when astrophysicists tracking the eccentricities of Mimas's orbit discovered that it exhibited a strange wobble which suggested that something unexpected must be happening down below its surface.

The first possible explanation put forward suggested that Mimas's huge distinctive impact crater, a feature that has earned it the nickname of 'Death Star', was harboring unusually dense rock that might be affecting its orbit. This theory was later rejected however as the size of the wobble is simply too great to be the result of a crater and something deeper down had to be responsible.Another, more plausible possibility, is that Mimas may have a subterranean ocean such as that seen on Europa or Enceladus which is sloshing around inside it and causing the wobble.

Whatever the explanation however the discovery has placed Mimas firmly back on the radar.

"Since the beginning of NASA's Cassini mission, Mimas was almost totally ignored, because it was thought to be just another boring [moon]," said astrophysicist Radwan Tajeddine. "But this is absolutely proof that Mimas deserves more attention."

Source: Popular Mechanics | Comments (8)

Tags: Saturn, Mimas