Pluto | The Dwarf Planet Formerly Known As A Planet

Interesting Fun Space Facts About Pluto!

• Pluto is believed to have formed during the accretion phase in the early solar system about 4.5 billion years ago. It didn’t merge with an existing planet or go on to grow big enough to become a planet.
• During the early 20^th century, the search for a ‘planet X’ beyond Neptune was carried due to observed changes in Uranus’ orbit. After a year searching photos of the night sky, the young astronomer Clyde Tombaugh found a ‘moving star’ which he’d been searching for.
• Disney’s lovable dog ‘Pluto’ was named after the newly discovered ‘planet’ in 1930.
• For the first 76 years after its discovery, Pluto was considered a planet. However, other dwarf planets like Makemake and Eris, were discovered from 2003 so in 2006 astronomers determined that Pluto was a dwarf planet like several other large objects discovered in the Kuiper belt region of the outer solar system.
• Pluto is (currently) the largest dwarf planet discovered. However, it is only the second most massive, with Eris being heavier!
• Pluto has an elliptical and tilted orbit compared to the planets. This means for 20 years of its 248-year orbit it is closer to the Sun than Neptune!
• On average Pluto is over 5.9 billion kilometres (3.7 billion miles) from the Sun, this is 39 times the distance Earth is from the Sun!
• With an axial tilt of 57°, Pluto basically orbits the Sun on its side, rotating backwards. This is similar to Uranus.
• Pluto is so far away, that the midday sunlight is 900 times dimmer than on Earth and it takes sunlight 5 ½ hours to reach it!
• Pluto has five known moons – Charon, Hydra, Nix, Kerberos and Styx. All names related to the god of the underworld.
• The largest moon Charon is half the size of Pluto, making it the largest moon relative to the body it orbits in the solar system! This is why some astronomers refer to Pluto & Charon as a ‘double dwarf planet’.
• Pluto’s surface is a complex mix of craters, valleys, water-ice mountains coated with methane snow and smooth plains made of nitrogen ice resembling a frozen lake!
• Pluto has a thin atmosphere made of nitrogen, methane and carbon monoxide when near perihelion. It freezes and falls as snow when Pluto is far from the Sun.
• The New Horizons probe, which launched in 2006, is the only spacecraft to have visited Pluto. After 9 1/2 years travelling across the solar system, the probe flew by the dwarf planet on July 15^th 2015 capturing stunning images while also studying this distant Kuiper belt object.