Dr. David Grinspoon is a planetologist at the University of Colorado, Boulder. He studies our nearest planetary neighbor, Venus. Venus may once have had oceans and life--although Grinspoon is among the doubters of this controversial possibility. Venus still has enormous rivers and lakes--but they are composed of solidified lava, rather than water. It is a planet of many surprises, including an odd ballistic coupling to the Earth.

Venus has a hellish surface, with average temperatures hot enough to melt lead, a surface pressure of 93 atmospheres, and an abundance of sulfur. Yet, as Grinspoon points out, people may one day live on Venus, hovering in balloons 50-65 kilometers above the planetary surface, where both the atmosheric temperature and pressure are earthlike. (Perhaps pirate ships will someday hide within and between the three distinct sulfuric cloud layers, fighting each other and sending each other to terrible deaths below.)

A brief bio and a review of Grinspoon's
Venus Revealed: A New Look Below the Clouds of Our Mysterious Twin Planet are given here.
David Grinspoon