Mariner 2 was the world's first successful interplanetary spacecraft. Launched Aug. 27, 1962, on an Atlas-Agena rocket, Mariner 2 passed within about 34,000 kilometres of Venus. Mariner 2 recorded the planet's temperature for the first time, revealing the its very hot atmosphere of about 500 degrees Celsius (900 degrees Fahrenheit). (NASA Media Archives). Buy this as a superb wall poster, a canvas print or a framed print.