The Tectonics of Venus

A tortured, volcanic wasteland, baked by a runaway greenhouse effect, the surface of Venus has clearly had an unpleasant history. But just how unpleasant has become the subject of renewed debate among planetary scientists trying to understand the planet's enigmatic topography.

Ever since NASA's Magellan spacecraft radar-mapped Venus twenty years ago, researchers have been struck by the relative sparseness and random distribution of its impact craters. The pattern, completely unlike that found on other terrestrial planets, suggests a surface that is uniformly young. A leading theory advanced to explain this is 'catastrophic resurfacing', the idea that between 300 million and 1 billion years ago, volcanoes covered most of the surface of Venus with molten flows and buried or destroyed any craters that existed then. Since that time--or so the story goes--Venus has been quiescent, its unchanging surface altered only by the random impacts of occasional asteroids.

But new research, some of which is due to be discussed at the 2010 VEXAG International Workshop in Madison, Wisconsin, this week, is refining this picture of Venus.…

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