Triton, the Canteloupe Moon
Neptune’s Triton is unlike any other Solar System body. Often called a “cantaloupe” for its weirdly variegated surface, marked by twisting, crumpled ridges, Triton is a bizarre world. The most distant of the major moons in the Solar System, Triton has characteristics of both classes of satellites—the big spherical ones and the tiny irregular ones. Triton is spherical and spans 1,682 miles, making it one of the largest moons known.
The moon orbits Neptune in a retrograde motion—that is, it travels in a direction opposite that of the planet’s rotation at all times. What makes Triton even stranger is its surface. It is young, contains geysers that vent nitrogen and dust, and has few craters. The twisting cantaloupe terrain seems to have formed from cold ammonia-rich material seeping upward.
 David J. Eicher, “Portrait of a Weird Moon,” Astronomy (42, 5, May 2014, p.9)