Venus, artwork. This is the second planet from the Sun, the next in from Earth and around 42 million kilometres further in, an average of 108 million kilometres from the Sun. Its diameter of 12,100 kilometres is slightly smaller than that of the Earth. Venus has a dense atmosphere of carbon dioxide and sulphuric acid clouds that obscure the rocky surface. The atmosphere traps the Sun's heat and leads to surface temperatures of over 500 degrees Celsius, the hottest planetary surface in the solar system. In addition, the atmospheric pressure on the surface is 90 times that on Earth.