The planet Venus is the second closest to the sun. Sometimes called Earth's twin due to its similar size, mass and density, Venus is a rocky terrestrial world with a number of unique features that are not found on the other planets within the solar system.
Slightly smaller than Earth, Venus has an orbital period of 225 days and a slow rate of rotation that results in a day that is longer than its year. Venus has no moons or rings, but does spin in the opposite direction of the other planets' rotations. Beneath its thick atmosphere, the surface of Venus is a barren volcanic landscape. The Venera 3 was a Soviet space probe that became the first man-made object to land on the surface of Venus.
Venus has an atmosphere made up of carbon dioxide with clouds of sulfuric acid. Atmospheric pressure is much higher on Venus, with a surface pressure some 90 times higher than that of Earth's. Venus suffers from a runaway greenhouse effect, and temperatures on the planet can reach up to 870 degrees Fahrenheit. Venus is sometimes called the Morning or Evening Star, as light reflected from the clouds that make up its atmosphere makes it one of the brightest and most easily recognized objects in the sky.