The Solar System consists of the Sun and everything that travels around it (planets, asteroids and comets). Astronomers think the Solar System is more than 4 billion years old. The eight main planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto is now a minor or a dwarf planet, it’s also the coldest planet and the furthest away from the Sun. Venus is the hottest planet, but the closest to the Sun is Mercury.
Mars is the nearest planet of the Solar System to Earth and it’s dry and small. It’s called the Red planet because it has a red, rocky surface. For some aspects it is similar to Earth. Its day lasts 25 hours and it has got volcanoes, valleys and ice caps that expand or withdraw according to the seasons. Billion years ago Mars also had an atmosphere, which could have allowed some sort of life. In the course of time the atmosphere vanished in the space, today Mars is only a frozen desert. It has two moons, Phobis and Deimos.
Uranus has eleven rings and fifteen moons. It consist of gases (methane, hydrogen and helium) and the atmosphere around it is a greenish colour. Uranus is a very cold planet, the average temperature is about – 205° C.
Jupiter is the biggest planet, it looks orange from space because it’s covered in orange clouds of gases. Very strong winds blow this clouds and cause huge storms. Astronomers think the planet core is a sphere of rock six times hotter than the Sun surface.
Saturn is nearly as big as Jupiter. We can see its rings from the Earth, they are very colourful and because of this scientists say that it’s the most beautiful planet. It has 18 moons, but some astronomers think that Saturn has more moons than this. Its moons came from a largest moon which broke up.