False-colour image of a corona on the surface of Venus, made by the Magellan radar-mapping spacecraft in 1991. The corona is situated about 1000km south of the equatorial continent Aphrodite Terra. It is about 375km in diameter, and flanks a north-south trending fault zone. The corona is thought to have been produced as a result of up- swelling of the surface by molten lava, creating a dome. As the dome cools, it collapses to form the corona. Coronae are generally found on lava plains. Just to the west (left) of the corona is a later dome made of lava that has reached the surface through a fissure. The black line is an area where insufficient data were gathered.