Outermost planet around the Sun. More massive, yet smaller of the two Ice Giant planets. First planet predicted by its gravitational effects. Its bright blue surface caused it to be named after the god of the sea. Has many large cloud features and storms that come and go. Generates more heat than it receives from the sun. Has one large possibly captured Kuiper belt object and several smaller moons. Orbit affects the objects in the Kuiper Belt, with many of them in resonant orbits with it. Visited by the Voyager 2 spacecraft.
Triton - Largest moon of Neptune, modestly larger than Pluto and Eris. In an irregular orbit, possibly a captured Kuiper Belt object. A capture method involving a binary moon of Triton has been proposed. Currently has a high inclination to Neptune, high axial tilt, and retrograde orbit, but tidal forces have given it a synchronous rotation and circular orbit, and it is nearer to its planet and much larger than other irregular satellites in the Solar System. Observed by Voyager 2. Found to have ice geysers and a thin but significant atmosphere.