Space & PhysicsJanuary 3, 2017
Carl Sagan's Extraordinary Career
He died 20 years ago, but while he is widely remembered as a brilliant communicator, he was no less brilliant a scientist
Stories by Christopher F. Chyba
Christopher Chyba is professor of astrophysical sciences and international affairs at Princeton University. For the past eight years, he has served on President Obama's Council of Advisors on Science and Technology (PCAST). He received his Ph.D. from Cornell University in 1991, where Carl Sagan was his thesis advisor, and his friend.
Space & PhysicsDecember 1, 1999
Is there Life Elsewhere in the Universe?
The answer is: nobody knows. Scientists' search for life beyond Earth has been less thorough than commonly thought. But that is about to change