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 chemical compounds are present only in trace amounts.
Venus in fiction
Others expected that the planet would have land masses, but not dry ones. In 1918, chemist and Nobel Prize winner Svante Arrhenius, deciding that Venus's cloud cover was necessarily water, decreed in "The Destinies of the Stars" that "A very great part of the surface of Venus is no doubt covered with swamps" and compared Venus' humidity to the tropical rain forests of the Congo. Because of what he assumed was constantly uniform climatic conditions all over the planet, the life of Venus lived under very stable conditions and did not have to adapt to changing environments like life on Earth. As a result of this lack of selection pressure, it would be covered in prehistoric swamps. Venus thus became, until the early 1960s, a place for science fiction writers to place all manner of unusual life forms, from quasi-dinosaurs to intelligent carnivorous plants. Comparisons often referred to Earth in the Carboniferous period.