The solar system

The Sun is a star at the centre of our solar system. Eight planets travel around it in paths called orbits: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first four are small and rocky. The outer four are huge and made mostly of gas and ice.

The Sun looks much bigger and brighter than other stars only because it is much closer to us. Other stars are so far away that they look like tiny dots. The Moon orbits the Earth about once a month, and the Earth orbits the Sun once a year, which takes about 365 days. Gravity keeps the planets in their orbits.