All the planets have got moons, except Mercury and Venus. Some moons are very big. For example, Saturn's moon, Titan, is bigger than the planet Mercury.

It's impossibile to land on Saturn, because it's made of gas. But its moon, Titan, is made of rock and ice.

In 2004, the mission Huygens landed on Titan and took photographs of Saturn and its moon. It doesn't look like a great place for a holiday and it's very cold!