Ten Interesting Facts About Pluto

Ten interesting facts about Pluto

Here is a list of some interesting facts about Pluto. A dwarf planet with a very different geology than previously thought, and despite being a small celestial body - Pluto has its own moons.

Pluto was known as the smallest planet in the solar system and the ninth planet from the sun until it was reclassified by the International Astronomical Union in 2006.

Today, Pluto is called a dwarf planet. A dwarf planet orbits the sun just like other planets, but it is smaller. It is large enough for its gravity to pull it into the shape of a ball but it is too small to clear other objects and debris out of its path around the sun.

Pluto was discovered on February 18th, 1930 by the Lowell Observatory. For the 76 years between Pluto being discovered and the time it was reclassified as a dwarf planet it completed under a third of its orbit around the Sun.

On average, Pluto is more than 3.6 billion miles (5.8 billion kilometers) away from the sun. That is about 40 times as far from the sun as Earth is. Pluto orbits the sun in an oval like a racetrack. Because of its oval orbit, Pluto is sometimes closer to the sun than at other times. At its closest point to the sun Pluto is still billions of miles away but is actually closer than Neptune.

This dwarf planet has five moons. Its largest moon is named Charon (KAIR-uhn). Charon is about half the size of Pluto. 

Pluto has four other, much smaller, moons. They are named Nix, Hydra, Kerberos, and Styx. They were discovered in 2005, 2005, 2011, and 2012, respectively. NASA’s Hubble Space Telescope took pictures of the new moons. All four are small.

Observations of Pluto’s surface by the New Horizons spacecraft revealed a variety of surface features, including mountains that reach as high as 11,000 feet (3,500 meters), comparable to the Rocky Mountains on Earth. While methane and nitrogen ice cover much of the surface of Pluto, these materials are not strong enough to support such enormous peaks, so scientists suspect that the mountains are formed on a bedrock of water ice.

Pluto’s surface is one of the coldest places in the solar system, at roughly minus 375 degrees Fahrenheit (minus 225 degrees Celsius). When compared with past images, pictures of Pluto taken by the Hubble Space Telescope revealed that the dwarf planet had apparently grown redder over time, apparently due to seasonal changes.

When Pluto is closer to the sun, its surface ices thaw and temporarily form a thin atmosphere, consisting mostly of nitrogen, with some methane. 

Pluto’s low gravity, which is a little more than one-twentieth that of Earth’s, causes this atmosphere to extend much higher in altitude than Earth’s.

sources: solarsystem.nasa and space.com

image credit: NASA/JPL - Lowell Observatory Archives