March 29, 2024
On this date in 1974, the unmanned probe Mariner 10 made its flyby of Mercury, passing at an altitude of 756 km. Photographs taken during the pass revealed an intensely cratered, Moon-like surface and a faint atmosphere made mostly of helium. Read a concise record of the Mariner 10 mission at NASA’s page here: https://solarsystem.nasa.gov/missions/mariner-10/in-depth/
The southern hemisphere of Mercury seen by the Mariner 10 spacecraft. Image credit: NASA.