Geology of Venus

Venus is a planet with striking surface characteristics. Most of what is known about its surface stems from radar observations, mainly images sent by the Magellan probe between August 16, 1990 and the end of its sixth orbital cycle in September 1994. Ninety-eight percent of the planet's surface was mapped, 22% of it in three-dimensional stereoscopic images.

The surface of Venus is covered by a dense atmosphere and presents clear evidence of former violent volcanic activity. It has shield and composite volcanoes similar to those found on Earth.

Relative to the Moon, Mars or Mercury, Venus has few small impact craters. This is likely a result of the planet's dense atmosphere, which burns up smaller meteors. Venus does have more medium-to-large-size craters, but still not as many as the Moon or Mercury.

Some other unusual characteristics of the planet include features called coronae (Latin for crowns, based on their appearance), tesserae (large regions of highly deformed terrain, folded and fractured in two or three dimensions), and arachnoids (for those features resembling a spider's web). Long rivers of lava have been discovered, as well as evidence of Aeolian erosion and tectonic shifts which have played an essential role in making the surface of Venus as complex as it is today.