Planet: pluto | Sunday Observer

Planet: pluto

26 March, 2017

What is Pluto like?

Up until 2006, Pluto was considered the 9th planet of the Solar System. At that time the IAU (International Astronomical Union) gave an official definition of a planet.

Pluto no longer qualified as a planet under this definition and was re-classified as a “dwarf planet”. Pluto is a relatively small planetoid, smaller than the Earth's moon. It is thought that Pluto is made up of a mantle of ice (mostly Nitrogen ice), which is about 50% of its mass, and a rocky core, which makes up the other 50% of its mass.

Pluto has a unique orbit around the sun. Rather than a round or circular orbit around the sun, like the 8 planets, Pluto's orbit is more egg-shaped. At its closest point to sun, Pluto is around 2.8 billion miles away. At its furthest point, it is around 5 billion miles from the sun. When Pluto is closest to the sun, it has a thin atmosphere. As Pluto moves away from the sun, it gets so cold that the atmosphere starts to freeze and fall to the ground.

Pluto has three named moons: Chiron, Nix, and Hydra. The largest is Chiron. There are two more moons that were recently discovered. Pluto and its moons are part of the Kuiper belt. 

How do we know about Pluto?

For nearly 100 years scientists had suspected there was a 9th planet somewhere beyond Neptune. This was based on changes in Neptune's and Uranus’ orbit that indicated a large mass was tugging on the planets. They called this mysterious 9th planet Planet X.

In 1930 a young astronomer, Clyde Tombaugh, found Planet X after a year of searching. 

How does Pluto compare to Earth?

Pluto has a hard, rocky surface like Earth. It is much smaller than Earth. Pluto is so far away from the sun, that it gets very little energy from the sun and is extremely cold. 

 

 

 

Comments