Jupiter and Io - one of the planet's many moons

After almost 40 years of space exploration, we now know that there are at least 95 moons spinning around the nine planets which orbit the Sun.

Looking at the surface of our own moon, it’s clearly a lifeless place. There’s no activity evident, apart from the constant bombardment of asteroids. 

We imagine the Earth’s polar ice-caps to be cold, forbidding places. Mars’ tiny twin moons, (Deimos and Phobos), have a temperature of a bone-chilling minus 170 degrees Fahrenheit. At minus 400 degrees Fahrenheit, Neptune’s moon (Triton) approaches absolute zero – the temperature at which all movement stops.

The atmosphere of the largest of Saturn’s five moons (Titan) is completely bereft of oxygen and there’s an abundance of nitrogen and cold methane instead that is believed to fall like rain. 

One of Jupiter’s moons is the warmest moon in the solar system. Io has spectacular volcanic eruptions that produce 45,000 tonnes of lava per second.

Perhaps the most interesting of all the moons in the solar system is Europa – the smallest of Jupiter’s satellites.  This moon has puzzled scientists ever since 1979, when the Voyager spacecraft sent the first images back to Earth.