Venus

Article By:

Tsang, Constantine Southwest Research Institute, Boulder, Colorado.

Last reviewed:August 2020

DOI:https://doi.org/10.1036/1097-8542.730100

Show previous versions

• Venus, published January 2014:Download PDF Get Adobe Acrobat Reader

The second planet in distance from the Sun. Venus has been called “Earth's twin” because it is similar to Earth in gross characteristics, such as mass, radius, and density (Fig. 1 and see table). In other ways, Venus is significantly different: Its atmospheric mass is almost a hundred times that of the Earth, with an atmospheric surface more than 90 times that of Earth; its atmosphere is mostly carbon dioxide, rather than nitrogen and oxygen; an extensive cloud layer of concentrated sulfuric acid is present; its surface temperature is a searing 464°C (867°F); it slowly rotates "backwards," or retrograde, on its axis, such that one Venusian day is equal to 243 Earth days, with the Sun rising in the west. Some of these differences are due more to alternate evolutionary paths of the two planets than to totally different initial conditions. See also: Atmosphere; Carbon dioxide; Cloud; Density; Earth; Mass; Nitrogen; Oxygen; Planet; Sulfuric acid; Sun; Temperature

The content above is only an excerpt.