All About Pluto

All About Pluto

By Madison Nef

Pluto was first seen by use of a telescope in 1930.  Like Uranus and Neptune, Pluto cannot be seen by the naked eye and its existence was not known to the ancient world. In 1930, the discovery of Pluto by Clyde Tombaugh in the Lowell Observatory was heralded as the discovery of the “ninth planet”. Even then, though… many astronomers did not agree or believe that Pluto had been discovered or that is should even be considered a planet.

In 2005 another possible planet, Eris, was found beyond Neptune, the eighth planet and since then 2 further small planet-like bodies have been discovered. These “planets” are not like any of the other planets in the Solar system. The reason for this is how they orbit the Sun. The first eight planets orbit the Sun in a path that they have cleared of all objects throughout time. Pluto, on the other hand, orbits the sun in a zone which is full of other objects that often pass between Pluto and the Sun. Since the planet was only discovered in 1930 and it takes 249 years to orbit the Sun, a full orbit has not been observed.

The first eight planets orbit the Sun while keeping the same distance from the Sun.  The Earth is always 93 million miles, one Astronomical Unit, from the Sun.  Pluto, however, orbits in an ellipse, an oval shape which means its distance from the Sun varies constantly.

In 2006, the International Astronomical Union agreed that these “planets” should be called “dwarf planets”. However, sizing had nothing to do with this decision- it’s all about the orbit. Of the nine planets (at least, nine when Pluto was planet), Pluto was the 2^nd smallest. Well… likely. Many argue that Pluto is slightly larger than Mercury, but it is not confirmed.

We know very little about Pluto.  NASA has sent the unmanned spacecraft ‘New Horizons’ to Pluto. While New Horizons left the Earth in 2005, it didn’t reach Pluto until 2015. It takes Pluto a staggering 248½ years to complete its orbit round the Sun.  The Earth takes one year (or 365 days).

Like all the other planets, Pluto turns on its own axis as it orbits round the sun.  Pluto takes about 6½ days to turn on its axis.  The Earth takes 24 hours, one day.

Since Pluto was the Roman God of the Underworld, and the planet was named after him… the planet’s main moon is named Charon after the ferryman who carries the dead souls across the River Styx into the Underworld. Pluto is known to have five moons. These moons are also named along the same lines- Charon being the largest, followed by Hydra, Nix, Styx and Kerberos.

Charon is mutually tidally locked to Pluto, and is so large that it is often considered a double-planet (or a double dwarf planet).

And there you have it! That wraps up this paper about Pluto- I hope you learned something. I know I did! Who would have known that Pluto hasn’t even made a full orbit of the sun since its discovery?

I’ll leave this here.

Maddie