Since its discovery in the 1930s until 2005, Pluto was a planet, the most distant from the sun. However when astronomers discovered the kuiper belt object Eris in 2003, its days of being a planet were numbered. Eris with its companion moon Dysnomia was calculated to be larger than Pluto. Scientists didn`t want to call it a planet and came up with a three point law on what constitutes a planet. In a vote at the end of a meeting of the International Astronomical Union, the world governing body for all things to do with space, a vote was held on the law and was passed. The requirement for a planet are :
The dwarf planet was spotted by Clyde Tombaugh as he scanned photos of the sky looking for any differences in the pictures.
Pluto was the last "planet" to be visited by a space craft but that is all about to change, the N.A.S.A. space probe, New Horizons is currently on route to rendezvous with the "planet" on or about 14th July 2015. New Horizons is the fastest space craft built to explore the outer regions of the space. It took Cassini-Huygens just over three years to reach the orbit of Jupiter, the New Horizons craft took a third of that time.
Disney named its cartoon dog Pluto in honour of the discovery, not the other way round. The planet was not named in any way by Pluto by competition or sponsoring.
Pluto had for most of the time it was known was seen as a lonely planet like Mercury and Venus but on the 22nd June 1978, its first moon was discovered by James Christy at the United States Naval Observatory. After New Horizons was launched, its other moons were discovered starting with Nix in 2005. All the moons are named after a connection to the underworld to keep consistent.
There is unlikely to be any lifeforms on Pluto. However, as the Sun grows, it will get bigger and the Goldilocks Zone will move out and one day that zone will encompass Pluto. By the time the zone reaches Pluto, Earth will no longer be able to support life as we know it. Hopefully by that time, humanity has managed to find a way off the planet and living further out than Pluto.
Scientists believe there might be another planet out beyond the orbit of Pluto, a new nineth planet. It is all theory at the moment but one day, we may well find out if there is any large planets out beyond Pluto. There might well be more than just one planet beyond Pluto, may be tens, all too faint to be spotted by telescopes at the present.
It is expected that after Pluto, the New Horizons will visit another Kuiper Belt object if N.A.S.A. can get the continued funding for it. Eris won`t be visited after Pluto as they are in different directions to one another.
|Position from Sun||9th but no longer class as planet, dwarf planet instead|
|Meaning||God of Death|
|Volumetric Mean Radius||1195|
|Orbital Period||90560 Days|
|Length of Day||153.282|
|Surface Pressure||-3 microbars|
|Distance from the Sun||5870000000km from the Sun.|
|Orbit Escape Velocity||1.1|
|Atmosphere||Methane (CH4), Nitrogen (N2)\n|
|Charon||June 22, 1978||110,181.80 km|