Planet Facts

There are 8 planets in our solar system; these are divided into two types, large gas giants (Jupiter, Saturn, Uranus and Neptune) and smaller rocky terrestrial planets (Mercury, Venus, Earth and Mars). The order from closest to the Sun outwards is; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and finally Neptune. Until 2006 Pluto was also classed as a planet, however it is now classified as a dwarf planet (meeting the first two requirements of the definition but not the third).

A planet is currently defined by the IAU (International Astronomy Union) as “a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.”

With the exception of Neptune and Uranus the other 6 planets can be seen unaided and all 8 are visible with a small telescope or binoculars. The largest planet in the solar system is Jupiter, followed by Saturn  Uranus, Neptune, Earth, Venus, Mars with the smallest being Mercury.

Order of the Planets

Order of the Planets

Facts about the Planets

Click on any planet below to find out more about it.