Louis Friedman is co-founder and former executive director of the Planetary Society.The three big questions about life — What is life? How did life originate? Is there extraterrestrial life? (Are we alone?) — are the raison d’être of space exploration. Life is why we explore.Yet despite exploring for all of human history, we have found only one example of life (that of Earth) and don’t know how it came to be. The mystery of how chemistry begot biology — that is, how the molecules of the univer...