Pluto, which now has a “minor planet designation” is a dwarf planet in the Kuiper belt which is a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered and is the largest known plutoid or ice dwarf.
Pluto is the largest and second most massive (after Eris) known dwarf planet in our Solar System. It is the ninth largest and tenth most massive known object directly orbiting the Sun. It is the largest known trans Neptunian object by volume but is less massive than Eris.
Like other Kuiper belt objects Pluto is primarily made of ice and rock and is relatively small, about one sixth the mass of Earth’s Moon and one third its volume. It has a moderately eccentric and inclined orbit during which it ranges from 30 to 49 astronomical units or 4.4–7.4 billion km’s from the Sun. This means that Pluto periodically comes closer to the Sun than Neptune, but a stable orbital resonance with Neptune prevents them from colliding.
One day on Pluto takes about 153 hours. Its axis of rotation is tilted 57 degrees with respect to the plane of its orbit around the sun, so it spins almost on its side. Pluto also exhibits a retrograde rotation; spinning from east to west like Venus and Uranus.
Light from the Sun takes about 5.5 hours to reach Pluto.