Planetology

Ellen Stofan is a planetary geologist who has conducted research on the geology of volcanic and tectonic features on Venus, Mars, Titan, and Earth. While an employee of NASA's Jet propulsion Laboratory (JPL) she was the Chief Scientiston NASA's New Millennium Program and the Deputy Project Scientist on the Magellan Mission to Venus. She is currently a Senior Research Scientist of Proxemy Research and an Honorary Professor of Earth Sciences at University College London. She lives with her husband and three children on a farm in Virginia.

Tom Jones is a scientist, author, pilot, and former NASA astronaut. He flew on four space shuttle missions and led three space walks to install the centerpiece of the International Space Station. He is the author of Sky Walking- An Astronaut's Memoir (Harper Collins, 2006) and the Complete Idiots Guide to NASA (Alpha, 2002) as well as a contributing writer to Smithsonian Air and Space magazine. He lives in the Viginia suburbs of Washington, D.C.