Uranus, Neptune and Pluto are the planets furthest from the Sun. they get very little of the Sun’s radiation so they are all dark and cold places. Uranus and Neptune are large planets made of gas. They look greeny-blue because they contain a gas called methane. Uranus is circled by nine rings, which are smaller than the rings around Saturn. The rings seem to be made of rocks and ice.
Pluto is the greatest mystery of all. It was only discovered in 1930 and is even smaller than our Moon. It is probably made of rock and covered in ice. Pluto is usually the outermost planet. But sometimes its orbit crosses Neptune’s for a period of 20 years, and then Neptune is the outermost planet. This last happened in 1979.
This artwork shows the Voyager 2 space probe as it passes Neptune’s North Pole.
An artist’s impression of Uranus and one of its many moons – it has at least 22 moons.
An artist’s impression of the planet Pluto and its moon Charon