Here are my top six candidates for the best spots to search for primitive alien life in our solar system.
FIRST STOP: Enceladus
Seth Shostak is a senior astronomer at the SETI Institute in Mountain View, Calif.
NEXT STOP: Mars
NEXT STOP: Titan
NEXT STOP: Europa
NEXT STOP: Venus, the Hellish Planet
But planetary scientist David Grinspoon, astrobiology curator at the Denver Museum of Nature and Science, points out that high in the Venusian atmosphere temperatures are refreshingly tolerable. Atmospheric sulfur dioxide and carbon monoxide might serve as food for floating microbes. Venus is 7,521 miles wide (12,104 km). [Venus, a Strange Planet Revealed (Photos)]
NEXT STOP: Callisto and Ganymede of Jupiter