Pluto By Amy O’Shannessy

Once a planet, Pluto is now a large dwarf planet in the Kuiper Belt.

Origins

Discovered by Clyde W. Tombaugh on February 18th 1930, Pluto orbited as a main planet in our Solar System from 1930-2006. However, several other planets were found, the same size or slightly larger than Pluto. Scientists could choose to claim their new findings as more main planets or demote Pluto to be a dwarf planet. Once a dwarf planet, Pluto was given the number 134340.

Name

Pluto is the only planet named by an 11 year old school girl. The name Pluto was proposed by Venetia Burney in Oxford, England.The name was suggested by Venetia during conversation with her grandfather, former worker at the University of Oxford’s Bodleian Library.The name was passed on to Professor Herbert Hall Turner, who forwarded it to his U.S. colleagues. It was up against Minerva (Which was already the name of a meteor), Cronus (Which lost all votes due to the fact it was proposed by a unpopular astronomer) and so therefore, Pluto received all votes. Miss Burney received 5 pounds in reward. The name was proposed because Pluto was the Roman god of the underworld and the seemingly cold, dark and barren planet was thought to suit. Pluto was officially named on March 24th 1930.

Appearance

Pluto has a rather colourful surface ranging between charcoal black, dark orange and white. Between 1994-2003, Pluto’s surface changed. The top became lighter and the southern pole darkened. This change was put down to an extreme axial tilt (An tilt of the axis- a somewhat imaginary line down the centre of the planet that the body revolves around-and so therefore, the planet moves.)

Size

2200 kilometers in diameter, Pluto is only 1% of the mass of Earth. It is only 1 fifth of the Earth’s moon’s size and 2 thirds of it’s diameter. This means it is second biggest dwarf Planet

Orbit

Orbiting once every 248 Earth years or 90,613.305 Earth days at a rate of 4.606 kilometers per hour, Pluto has a strange orbit. During part of this strange orbit, Pluto becomes inward of Neptune. This hasn’t been done since between February 7th 1979 and February 11th 1999 and in 1989 became within 445,500,000 kilometers of the Sun. This isn’t expected to happen for another 230 years. Although it sometimes comes closer to the Sun than Neptune, it can be as far as 7,395,000,000 kilometers from the Sun.

The cold and barren dwarf planet named after the Roman god of the underworld is no longer one of our main planets, and will never be as important as it once was, but will still remain a interest to many astronomers.