Fifty years ago today, on March 13, 1975 (February 1, 1975 lunar calendar), the US "Mariner 10" probe made its third flight close to the surface of Mercury. The "Mariner 10" probe launched in 1973 made its third flight close to the surface of Mercury on March 13, 1975. The US "Mariner 10" probe sent back hundreds of valuable Mercury photos and data from outer space to Earth in a week. These photos and measured data are very valuable for scientists to determine the nature of the planet. The "Mariner 10" probe was launched in November 1973 to detect Mercury. Now the probe has lost its function and is drifting in space. 1962 US "Mariner" 1 Destination: Venus "Mariner" 2 Venus probe launched in 1962 "Mariner" 5 Venus probe launched in 1967