It's distance from the Sun is 36 000 000 miles or 57 910 000 km. It's temperature variations are the most extreme in the solar system, ranging from 806 ºF (430 ºC) on the day side to -297 ºF (-183 ºC) on the night side.
Mercury orbits the Sun every 87.97 days and is the fastest moving of all the planets. Its surface is not unlike our Moons with craters from meteorites covering the planet. Dust from all the impacts covers everything. The largest known feature on Mercury is the Caloris Basin which is 1350 km in diameter. It is believed to have been made around the time of the planets birth, estimated at over 4 billion years ago.Mercury has no known satellites or moons.
It made three passes around the planet between 1974 and 1975.
The first fly past was on March 29, 1974 at a distance of 705 kilometers.
The second was on September 21, 1974 and the third was on March 16, 1975.
Below is a bigger picture of Mariner 10 and one of it's images of Mercury
