Venus is the closest planet to Earth, and yet it retains an aura of mystery. The thick layer of clouds hiding its surface has long frustrated efforts to take a close look at the Venusian landscape.
Now the veil is coming off. Last week NASA's Magellan spacecraft transmitted the most detailed pictures ever made of Earth's next-door neighbor. The radar images revealed a tortured topography with fault-like cracks in surprisingly regular patterns, craters as big as greater Los Angeles and volcanic mountains flanked by congealed rivers of lava at least 320 km (200 miles) long. Says James Head III, a Brown...