Illustration of the Venera 8 probe approaching the surface of Venus. This probe was launched by the USSR on 27th March 1972 and entered the Venusian atmosphere on 22nd July 1972. It survived on the planet, which has the hottest planetary surface in the solar system, with temperatures of nearly 500 degrees Celsius, for 50 minutes. During that time it measured the temperature and light levels on the surface, and conducted the first analysis of the surface rock.