• Discovered by Clyde W. Tombaugh on February 18, 1930, Pluto is the second-most-massive known dwarf planet in the solar system (after Eris) and the 10th most-massive body observed directly orbiting the sun.
• Originally classified as the ninth planet from the sun, Pluto was re-categorised as a dwarf planet and plutoid due to the discovery that it is only one of several large bodies within the Kuiper belt.
• Like other members of the Kuiper belt, Pluto is composed of rock and ice and is relatively small: approximately one-sixth the mass of the earth’s moon and one-third its volume.
• It has an eccentric and highly inclined orbit that takes it from 4.4-7.4 billion kilometres from the sun.
• This causes Pluto to periodically come closer to the sun than Neptune.