What are the planets?

Earth is not alone in space. It is one of eight planets that travel around the Sun, like a big family circling the same warm fire.

A planet is a world that circles the Sun

A planet is a huge, round world that loops around the Sun. Earth is a planet, and so are its neighbours. Each one follows its own path, called an orbit, going round and round without ever bumping into the others. The Sun’s gravity holds them all in place.

Eight very different worlds

There are eight planets. The ones near the Sun — Mercury, Venus, Earth and Mars — are made of rock, like our own world. The far-off ones — Jupiter, Saturn, Uranus and Neptune — are giant balls of gas and ice, much bigger than Earth. Saturn even wears beautiful rings made of ice and dust.

Earth is just right

As far as we know, Earth is the only planet with exactly what living things need: air to breathe, water to drink, and a comfy warmth that is not too hot and not too cold. That is why people, animals and plants all make their home right here.

Wonder fact: A year on Mercury, the planet closest to the Sun, is only 88 days — it races around super fast. Faraway Neptune takes 165 Earth years to go round even once!