On March 29, 1974 Mariner 10 flew by the parched little world Mercury. During it's mission Mariner 10 obtained detailed photographic coverage which changed the closest planet to the Sun from a difficult fuzzy telescopic object to a new world opened up for geologic study. This is a mosaic of the 'outgoing' hemisphere seen during the first of three encounters. Scanned from an original print. 640K

The second flyby of Mariner 10 on September 10, 1974 allowed the innermost planet to be studied from another angle. The flyby timing was such that the same hemisphere was lit for all three encounters. The Messenger spacecraft will orbit Mercury and finally reveal the entire planet. 1.2MB