VENUS' VOLCANIC SURFACE

Below Venus' thick deadly cloud cover is a planet of deep valleys and massive volcanoes. This was only discovered ten years ago during the Magellan mission which orbited Venus from 1990-1994 and took pictures of the planet to give us a global map of it using radar imaging equipment which could see through the clouds. Scientists discovered that the planet has 167 volcanoes which are larger that 100 kilometres across (only one volcano is this large on Earth) and over 50,000 smaller volcanoes. During the Magellan mission, which used spare parts from missions to other planets to keep the costs down, no volcano erupted. This disappointed scientists who were secretly hoping that the planet was geologically active like Earth and still forming.

There are no signs of water on Venus, although there may have been millions of years ago. It may have boiled away as the planet got hotter. As the planet warmed up, rivers of water appear to have been replaced by rivers of hot lava. Some scientists believe that, about 200 to 800 million years ago, the entire surface of the planet was reformed when volcanoes erupted all over it and covered its surface in lava. This explains why there are very few craters on the planet's surface, compared with planets like Mercury which are billions of years old. In this way, Venus is similar to Earth, which is also quite a young planet with very few craters. Venus also has some strange features on its surface: domes which look like pancakes and volcanoes without their usual spouts.

Pictures of Venus' surface taken by Magellan's radar imaging equipment. The left picture shows a group of volcanoes, the middle picture is a volcano which appears to 
have sank in the hot magma below it, and the right picture show mysterious volcanoes which look like pancakes on the planet's surface!