Mariner 2

Mariner 2 was an American space probe launched on August 27, 1962, that was the first robotic space probe to successfully report from a planetary encounter, passing as close as 34,773 kilometers to Venus on December 14, 1962. The spacecraft was a simplified version of the Block I spacecraft and carried scientific instruments including two radiometers, a micrometeorite sensor, and a magnetometer, which measured temperature distribution, atmospheric properties, and interplanetary magnetic field and charged particle environment. During its journey, Mariner 2 measured the solar wind, interplanetary dust, and high-energy charged particles, and its radiometers revealed cool clouds and an extremely hot surface of Venus.learn more on wikipedia