The Planets

Relatively few craters mar the new face of Venus, since the rate of cratering over these past 500,000 years is much reduced from the Solar System’s earliest days. Many small would-be intruders are vaporized on their way through the thick atmosphere, never to touch down, so that only the very largest impactors reach the surface intact. These collisions eject copious debris, yet all the rubble hugs close around the crater margins in neat festoons, as though contained there by the heavy air. The atmosphere likewise may have soothed the fury of Venusian volcanoes, compelling their expelled lava to seep and pour rather than erupt with explosive force.