Venera 3, a Soviet probe launched from Kazakhstan on November 15, 1965, collides with Venus, the second planet from the sun. Although Venera 3 failed in its mission to measure the Venusian atmosphere, it was the first unmanned spacecraft to reach the surface of another planet. Four years earlier, the U.S. probe Mariner 2 was the first spacecraft to pass close enough to Venus to take scientific measurements of the planet, discovering surface temperatures in excess of 800 degrees Fahrenheit on its surface.
In 1967, Venera 4 succeeded where Venera 3 failed, successfully ejecting several scientific instruments, including a thermometer, a barometer, an atmospheric density gauge, and gas analyzers, into Venus' atmosphere. Then, in 1970, Venera 7 became the first spacecraft created by humans to soft-land on Venus, successfully sending back images and data for 23 minutes before succumbing to the extremely high temperature and atmospheric pressure found on the planet's surface.