Max Brooks

Mariner 2

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 kilometers (21,000 miles) of Venus, sending back valuable new information about interplanetary space and the Venusian atmosphere. 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). The spacecraft's solar wind experiment was the first to measure the density, velocity, composition and variation over time of the solar wind.

NASA Image of the day archive  NASA