Uranus's moon Miranda has features called coronae, at least one of which has a depth probably exceeding the Challenger Deep low point of the Mariana Trench - estimated at 10 to 20 kilometers, vs. Challenger Deep's 10.4 kilometers.

Alternatively, the Kola Superdeep Borehole SG-3 has a depth of over 12.2 kilometers, also deeper than Challenger Deep.