Erik Petigura and Geoffrey Marcy discuss the number of Earth-like planets that may exist in our galaxy.

Interview with 2013 Cozzarelli Prize Winners Mimi Kao and Allison Doupe

Welcome to Science Sessions, the PNAS podcast program. Listen to brief conversations with cutting-edge researchers, Academy members, and policymakers as they discuss topics relevant to today's scientific community. Learn the behind-the-scenes story of work published in PNAS, plus a broad range of scientific news about discoveries that affect the world around us.