Mercury is the closest planet to the Sun, and is named after the Roman messenger of the gods. If you prefer your Greek tragedies to Roman then he is known as Hermes (and yes, I did just called the planet Him). It orbits the Sun once every 88 days, and has the fastest orbit of any of the planets. It is one of four terrestrial planets in the Solar System, these are ones that are rocky instead of gassy. It is also the smallest planet in the Solar System (some of the other planets have moons bigger than Mercury!).
It has had two visits from spacecraft; Mariner 10 which flew past it in the 70s and Messenger which is still orbiting the planet today! It gets really hot and really cold on Mercury with the hottest being about 400 degrees Celsius, and the coldest being about -170 degrees Celsius (wouldn't be my choice for a holiday in space anyway..). It doesn't seem to have much of an atmosphere left due to this being blown away by the Solar Wind (saving this for another post), so there isn't any weather or water on Mercury!
So what do you think of this series? Do you feel sorry for poor hot/cold lonely Mercury?