Venus and its rocky surface, illustration. Venus, the second planet from the Sun, is a rocky world that is only slightly smaller than the Earth. Sulphuric acid cloud layers (not shown here) obscure the surface. The dense carbon dioxide atmosphere (not shown here) traps the Sun's heat, leading 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. Venus is the brightest planet seen from Earth, and is often visible to the naked eye. The surface has been mapped by radar by visiting space probes.