Mimas was a moon of Saturn (PROSE: To the Slaughter) that was a dirty lump of ice with a little rock under the surface.
Herschel Crater was almost half the size of the moon. (PROSE: So Vile a Sin)
The Fifth Doctor claimed he knew Kolkokron like the back of Mimas. (PROSE: Life After Queth)
On 26 August 2982, the Seventh Doctor and Chris Cwej located the Nexus on Mimas. (PROSE: So Vile a Sin)
Muldwych wanted to visit Raphael on Mimas. (PROSE: Happy Endings)