Venus

Venus is brightest of all the planets and is slightly smaller than the Earth. Being closest to the Earth passing at a distance of 39,000,000 km away. It is often visible in the morning and evenings, this specialty has given it the name "Morning Evening Star". Venus is named after the Roman goddess of love and beauty and it is veiled by thick swirling clouds.

Venus is very different from the Earth. It has no oceans and is surrounded by a heavy atmosphere composed mainly of carbon dioxide with virtually no water vapor. Its clouds are composed of sulphuric acid droplets. At the surface, the atmospheric pressure is 92 times that of the Earth's at sea-level.

Venus is scorched with a surface temperature of about 482° C (900° F). This high temperature is primarily due to a runaway greenhouse effect caused by the heavy atmosphere of carbon dioxide. Sunlight passes through the atmosphere to heat the surface of the planet. Heat is radiated out, but is trapped by the dense atmosphere and not allowed to escape into space.

Venus is scarred by numerous impact craters distributed randomly over its surface. Small craters less that 2 kilometers (1.2 miles) are almost non-existent due to the heavy Venusian atmosphere. The exception occurs when large meteorites shatter just before impact, creating crater clusters. Volcanoes and volcanic features are even more numerous. At least 85% of the Venusian surface is covered with volcanic rock. Hugh lava flows, extending for hundreds of kilometers, have flooded the lowlands creating vast plains. More than 100,000 small shield volcanoes dot the surface along with hundreds of large volcanoes. Flows from volcanoes have produced long sinuous channels extending for hundreds of kilometers, with one extending nearly 7,000 kilometers (4,300 miles).

Giant calderas more than 100 kilometers (62 miles) in diameter are found on Venus. Terrestrial calderas are usually only several kilometers in diameter. Several features unique to Venus include coronae and arachnoids. Coronae are large circular to oval features, encircled with cliffs and are hundreds of kilometers across. They are thought to be the surface expression of mantle upwelling. Archnoids are circular to elongated features similar to coronae. They may have been caused by molten rock seeping into surface fractures and producing systems of radiating dikes and fractures.