It's the Golden Jubilee of the Apollo 15 Mission

Fifty years ago, on July 26, 1971 NASA launched the Apollo 15 mission. It was NASA's 9th crewed mission and also the first one to use the Lunar Roving Vehicle - a battery-powered 4-wheeled rover built by Boeing. The LRV had a restricted range of about 9.5 Km from the lunar module; and was designed to operate for a total of 78 hours during the lunar day (which lasts for about 29 days). These cars were left parked on the surface of the moon to wait for the next generation of astronauts.