"No planets that we knew of had experienced volcanic eruptions of this scale and speed," Bond said in a BBC-TV interview.
So, a single, titanic volcanic event may not have been responsible for smoothing out the Venusian surface. Instead, a series of volcanic eruptions-more like Earth's supervolcanoes of the Yellowstone kind, even smaller-were more likely to have resurfaced Venus 500 million years ago. But what triggered these more modest series of volcanic eruptions that reshaped a planet the size of Earth? Ah-now there you have a real mysery.
Lou Varricchio, M.Sc., is a former senior science writer at the NASA Ames Research Center in California. He is a current member of the NASA-JPL Solar System Ambassador program in Vermont. You can contact him at: email@example.com.