The SciencesJanuary 6, 2016
If There Are Aliens Out There, Where Are They?
Alien life, if it exists, could be as simple as bacteria or more complex than humans—and there are optimal strategies for searching for both
Stories by Joe Silk
Joseph Silk is Homewood Professor of Physics and Astronomy atthe Johns Hopkins University in Baltimore and a researcher atInstitutd'Astrophysique de Paris and Service d'Astrophysique, CEASaclay in France. He has published more than 700 articles and several popular books.