Jupiter is by far the biggest of the planets. It is a giant gas ball that has twice as much mass as all the other planets put together. It could swallow more than 1,300 Earth’s!

Jupiter is very much farther away than Mars, but often appears much brighter. This is because it is very much bigger and has a cloudy atmosphere that reflects sunlight well.

Through a powerful telescope we can see bands on the face, or disc, of Jupiter. We call the dark ones belts and the light ones zones. Among the bands light and dark spots come and go. We can see them moving across the disc as the planet spins very rapidly on its axis. One spot has been visible for at least three centuries. It is called the Great Red Spot because of its huge size and colour.

Space probes have taken close-up pictures of the belts and zones on the disc. They seem to be clouds that have been pulled out into bands as Jupiter and its atmosphere spin round.