There were perhaps one hundred billion galaxies in the universe, and each galaxy contained a hundred billion stars. How many of those stars had planets, and how many planets had life? Panspermia, the theory that life exists and is distributed throughout the universe, was no longer merely speculation. The belief that there was life only on this pale blue dot, in this insignificant solar system, now seemed as absurd as the ancients' naive belief that the sun and the stars revolved around the earth. The