Facts about Pluto


Fact: General facts about Pluto


Pluto is a dwarf planet that orbits the sun beyond the orbit of the 8th planet, Neptune. It was first discovered by telescope in 1930 by American Clyde Tombaugh, and was considered a planet for 76 years. In 2006 after discovering other celestial bodies orbiting near Pluto and of similar size, astronomers invented the term ‘dwarf planet’ with Pluto being the most well known. The first space craft to visit Pluto at close range was New Horizons in 2015.

Facts About Pluto

Name Origin: Greek. Because it is so small and distant, Pluto was only discovered by telescope in the 20th century. After discovery astronomers debated the names Zeus, Percival and Constance. It was eventually an 11 year old English schoolgirl Venetia Burney, who proposed the name Pluto after her interest in mythology.

Size: Average Diameter 2,360km, Mass of approximately 1.3 x 10^22 kg. Pluto is less than 70% the size of the Moon. Even this small it has its own moon Charon that is more than half the size of Pluto!

Gravity: 0.063g. Because of Pluto’s small size, the gravity on the surface is very weak. If you weight 150lbs on Earth you would weigh only 9.45 lbs on pluto. A Basket ball player who could jump 1 meter high on Earth, could jump more than 14 meters high on Pluto, and take more than 12 seconds to land!

Temperature: The surface temperature of Pluto averages a very chilly -230 degrees C!

Days: Rotational period 153 hours. Pluto spins quite slowly. Every one day on pluto is more than 6 days on Earth!

Orbit: Semi Major Axis: 5.8 billion km, Orbital Period 248 years. Pluto is almost 50 times further away from the sun than the Earth, and takes nearly 2 and a half centuries to make just one orbit. It also orbits at a different angle than the 8 major planet, orbiting at an ‘inclination’ which is more than twice that of Mercury.

Atmosphere: Nitrogen, methane, carbon monoxide. Pluto has a very thin atmosphere, less than 100,000 times the pressure as found on Earth. When Pluto is furthest away from the sun, it gets so cold that the entire atmosphere freezes and forms ice over the surface.

Visible Features: Pluto has very high contrast in colors and brightness on its surface. Made mostly of nightrogen ice, it has colors varying between black, dark orange, and white. The most dramatic feature is called the Tombaugh Regio which is a bright white area in the shape of a Heart!!

Fun facts: With the space probe New Horizons visiting Pluto in 2015 astronomers are learning more details about Pluto and its moons than in all the decades after its original discovery combined!

To learn more about Pluto visit:

  • Pluto: King of the Kuiper Belt