Discovering Venus: Facts about Earth's Mysterious Sister Planet.

Venus, Earth's "sister planet," is covered in thick clouds that make the weather inhospitable to life but extremely stable. Every day is cloudy and 900 degrees Fahrenheit, and the atmosphere is heavy, exerting a force that would crumple the human body. Venus rotates so slowly that a day on this planet is longer than its year. Venus can best be seen just before sunrise or just after sunset, depending on where it is in its orbit. In 1990, NASA's Magellan spacecraft became the first mission to orbit Venus and map its surface.