Object Analysis

Mimas is a moon of Saturn discovered in 1789 by William Herschel. It is the smallest of the "major" moons of Saturn and is famous for its striking resemblance to the "Death Star" from Star Wars. This is due to the enormous Herschel Crater, which spans 130 km—nearly one-third the diameter of the moon itself.

The impact that created Herschel Crater nearly shattered Mimas. If the moon were much smaller or the impact much larger, it likely would have broken apart. Beyond this crater, Mimas is a heavily cratered, geologically inactive world of water ice and rock with very low density.

Recent data from the Cassini mission suggests that Mimas may have a surprisingly "wobbly" rotation, which could point to either a non-spherical core or a thin subsurface ocean. However, the lack of surface cracks or geysers (like those on Enceladus) makes the ocean theory a subject of intense debate among planetary scientists.