Humanity has been aware of Mercury since at least the time of the Sumerians (3000 BC). It was given two names by the Greeks: Apollo, when it it appeared as a morning star and Hermes as an evening star. It is interesting to note that the Greek astronomers knew that they were the same stellar body. Heraclitus believed that Mercury and Venus orbit the Sun and not the Earth.

Mercury is the second-smallest planet in our Solar System (after Pluto). Mercury is a more than a third of the diameter of the Earth. Mercury is only slightly larger than the Earth's moon.

NASA has launched a new craft to get us more information about Mercury. It is called MESSENGER and it was launched 08/03/2004 and it is expected to arrive 06/06/2007. We're really looking forward to new info on the little planet next to the Sun.