Solar System
Pluto Art   Pluto
An artist's impression of distant Pluto and its moon, Charon. The Sun is in the top right corner.
Image copyright ESO
The best actual picture of Pluto taken with the Hubble Space Telescope. The big objects are Pluto and Charon. The small dots are the two other moons, Nix and Hydra.

Pluto is the most distant planet although some people would say it's not a planet.

It was discovered in 1930 by Clyde Tombaugh who found it by analysing photographic plates.

It is the smallest planet and in 2006, the IAU demoted it to a 'minor planet'. A good argument for Pluto not being a planet is that most things in the Universe come in pairs. If Pluto isn't a planet, then the Solar System has two pairs of four rocky planets and four gas giants.

Demoting the planet was a controversial decision and many people protested and some still regard it as a planet.

In 1978, Christy discovered the moon called Charon. Currently, not much is known about this moon. Also in 2006, the Hubble Space Telescope discovered two additional moons called Nix and Hydra.

    Image copyright NASA/ESA/H. Weaver/A. Stern/
Hubble Pluto Companion Search Team

Name: Pluto

Distance from Sun: 3,670,050,000 miles

Diameter: 1430 miles

Length of Day: 6.4 days

Length of Year: 248 years

Number of moons: 5


Not a single probe has visited Pluto because of its great distance. Fortunately NASA launched the New Horizons probe in 2006, which will hopefully unravel its mysteries. The reason the probe will reach there is because it has an ion propulsion system which makes it a bit faster. It will hopefully get there in 2015 if it doesn't get destroyed or if it doesn't malfunction.