Atmosphere of Venus Atmosphere of Venus The atmosphere of Venus is the layer of gases surrounding Venus. It is composed primarily of carbon dioxide and is much denser and hotter than that of Earth. The temperature at the surface is 740 K (467 °C, 872 °F), and the pressure is 93 bar (9.3 MPa), roughly the pressure found underwater on Earth. The Venusian atmosphere supports opaque clouds made of sulfuric acid, making optical Earth-based and orbital observation of the surface impossible. Information about the topography has been obtained exclusively by radar imaging. Aside from carbon dioxide, the other main component is nitrogen. Other
Atmosphere of Jupiter comprehensively understood of those of all the gas giants because it was observed directly by the "Galileo" atmospheric probe when it entered the Jovian atmosphere on December 7, 1995. Other sources of information about Jupiter's atmospheric composition include the Infrared Space Observatory (ISO), the "Galileo" and "Cassini" orbiters, and Earth-based observations. The two main constituents of the Jovian atmosphere are molecular hydrogen () and helium. The helium abundance is relative to molecular hydrogen by number of molecules, and its mass fraction is , which is slightly lower than the Solar System's primordial value. The reason for this low abundance is