Venus the second planet from the Sun is Earth's near twin in size is the brightest planet in the night sky apart from the Sun and the Moon. It is located 0.7 Astronomical Units from the Sun. For centuries, astronomers lacked a view of Venus' surface and could only calculate its size and motion. Venus has a diameter of 7,521 miles (12,104 km), about 5 percent smaller than Earth's and orbits the Sun every 225 day.
In 1962 radar enabled scientists to measure Venus' 243-day spin, which surprisingly goes backward (retrograde) compared with most other planets. The sun rises in the west and sets in the east, opposite what we see on Earth. From one sunrise to the next on Venus takes 117 Earth days.
Venus is hidden beneath a blanket of deep yellowish clouds made up of sulfuric acid. The top layers are very cold but down near the surface they heat up. Most of Venus' air is carbon dioxide. Venus' air is a never-ending storm, with continuous thunder and lightning. Although Venus is farther from the Sun than Mercury it is much hotter. The Sun's rays go down through Venus' air and heat the surface rocks. The carbon dioxide acts as a blanket that traps the heat given off by Venus' surface. This produces a greenhouse effect because the Sun's heat is trapped.
Venus has many craters, but they have been worn down by weather. Venus' highest mountain is named Maxwell Montes. It stretches up 100,000 feet (30,300 meters) and appears to have a volcanic crater. Venus has one of the largest canyons in the Solar System. It is nearly four times larger than the Grand Canyon and twice as deep.
Like Mercury, Venus is sometimes called the "morning star" and "evening star". Because its orbit has it revolving relatively closer to the sun, Venus is easiest to spot right before the Sun goes down, or right before it rises.