Uranus has five satellites that are about the same size as the group of six Saturnian satellites mentioned above. It also has a large number of much smaller moons including possible shepherds. These are darker but still seem to be generally similar to Iapetus, etc. They revolve around Uranus in the equatorial plane of that planet, i.e. they are tipped with respect to ecliptic. Neptune has one large, major satellite Triton plus a number of small moons.
Triton is retrograde, i.e. it revolves around Neptune in opposite sense to Neptunian rotation.
As such, the tides are causing it to move closer to Neptune rather than farther away as is the case with the Moon, for example. Triton has a thin nitrogen atmosphere, polar caps of methane and nitrogen ice, and geysers of nitrogen. Pluto and Charon Percival Lowell predicted the planet Pluto due to certain discrepancies in the orbits of Neptune and Uranus that couldn t be explained with the known planets. Years later, in 1930, Clyde Tombaugh discovered Pluto while working at Lowell Observatory in about the place Lowell predicted. However, the planet that Lowell needed in his calculations was the size of Uranus and Neptune, about 20-x mass of Earth.