Triton is a very bright moon of Neptune. This moon is made of huge fields of methane, and Nitrogen which give Triton its beautiful red color. Triton may have been a small planet that got too close to Neptune's gravitational pull. It probably ran into another moon which slowed it enough to start orbiting Neptune. Triton will someday fall and crash into Neptune. Because Triton reflects most of the heat that reaches it, it is the coldest object in the solar system.
