Welcome to your Fact File on the planet Mercury!

Mercury is the smallest planet in our Solar System and it orbits closest to the Sun. On either side of Mercury you can find Venus and Earth.

The surface of Mercury looks like our Moon made up of many craters. There is no atmosphere on Mercury which means that the temperature is really cold in the night and really hot during the day. Since Mercury is so close to the Sun, the temperature during the day can get up to 427° Celsius!

One interesting thing about Mercury is that it does not have any moons or rings like other planets. Gravity on Mercury is one third of that on Earth, which means that if you weighed 45 kg (100 lbs) on Earth, you would weigh only 15 kg (33 lbs) on Mercury!

Despite its unforgiving environment, Mercury still holds a place of great mystery since no one has ever gone there except spacecraft. NASA's spacecraft Messenger has orbited Mercury since 2011 and has discovered many cool things such as mountains, snow, ice and an ocean of liquid metal! Mercury is composed mostly of oxygen, potassium, and magnesium.

Mercury is known as the Winged Messenger because of one of its symbols. It is also famous for being the planet with the fastest orbit around the Sun of all the planets.

So that’s your fact file about Mercury! But don’t forget that Mercury is very far away and no one can really visit it.