In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

The Tano Sulcus bisects part of this bodys surface. Its motion is technically anti-synchronous with respect to the object it orbets. Found by William Lassell, its so-called cantaloupe terrain is probably caused by cryovulcanism and its atmosphere consists largely of hydrocarbons, including methane. For ten points, name this largest moon in the solar system with a retrograde orbit, the most massive moon of Neptune.
Science