The mystery below the clouds
Venus is the brightest object in the sky, after the Sun and the Moon. Like Mercury, Venus can be generally seen in the morning or in the evening sky, in the Northern Hemisphere.
The pressure of the atmosphere at the surface is 90 atm. The densest clouds are at a height of 50 km, but their thickness is only 2–3 km.
The diameter of Venus is about 12,000 km, similar to that of the Earth.
Venus is covered by clouds, such that its surface is nowhere visible, indeed only featureless yellowish cloud tops can be seen. The rotation period remained for long unknown. In 1962, radar measurements revealed that the rotation period is 243 days in a retrograde direction, which means that it is opposite to the rotation of other planets and the axis of rotation is almost perpendicular to the orbital plane.
About 1% of the incident light reaches the surface of Venus; this light is deep red after travelling through clouds and the thick atmosphere. Most of the incident light, about 75%, is reflected back from the upper layers of clouds. The absorbed light is emitted back in infrared. The carbon dioxide atmosphere very effectively prevents the infrared radiation from escaping, and the equilibrium temperature is around 750 K.
Most of the Venusian impact craters are undeformed. This indicates that the Venusian surface must be young because erosion, volcanism and tectonic forces should affect the craters, too.
If you want more in depth content, all the news and the articles, plus educational content about Space, written by experts and engineers, just visit our website and join the SpaceInfo Club: it's free. Join our members club!
Comments