“Mimas appeared like an unlikely candidate, with its icy, closely cratered floor marked by one large impression crater,” stated second creator Dr. Alyssa Rhoden, a specialist within the geophysics of icy satellites, at SwRI.

Source: https://www.mccourier.com/what-makes-saturns-moon-mimas-look-like-the-death-star-is-new-evidence-for-an-underground-ocean-say-shocked-scientists/