Pluto is a dwarf planet in the Kuiper belt, a ring of bodies in the outer Solar System beyond Neptune. Pluto used to be known as the ninth planet but in 2006 was re-classified. We no longer think of it as the outermost major planet, but the first dwarf planet of the Kuiper belt.
Facts About Pluto:
- Pluto is smaller than Earth's Moon.
- A year on Pluto lasts 248 Earth years. The planet was discovered in 1930 and "demoted" to dwarf planet status in 2006, meaning that it was known as a planet for less than one of its own years.
- The first close-up images of Pluto were recorded by NASA's New Horizons robotic mission in 2015.
Discovered: 1930 by Clyde Tombaugh
Naming: Greek god of the underworld. The name was suggested by Venetia Burney (1918-2009), an 11YO schoolgirl from Oxford, England.
Magnitude: 13.6500 (app) -0.7000 (abs)
Rotation period: -6 days 9 hrs 17 mins
Atmosphere: nitrogen, methane, carbon monoxide