Last updated on April 16, 2014 at 6:17 EDT
Mariners Mercury
15 of 15

Mariner's Mercury

March 17, 2003
Mercury, the closest planet to the Sun, remains the most mysterious of the Solar System's inner planets. The only spacecraft to explore Mercury close-up was Mariner 10 which executed 3 flybys of Mercury in 1974 and 1975, surveying approximately 45 percent of its surface.