
Our Cosmic Context
May 5, 2014 explains how investigations into life on other planets help us to understand Earth's challenges.
Caleb Scharf is Director of Astrobiology at Columbia University. His next book, The Copernicus Complex, will be published in September 2014.
May 5, 2014 explains how investigations into life on other planets help us to understand Earth's challenges.
Nearly three months after Russia launched its invasion, Western countries appear more committed than ever to Ukraine’s defense, and, in some quarters, to Russia’s defeat. We asked PS commentators what outcome the West, Russia, and Ukrainians themselves can realistically expect.