Space Invaders

The stuff of life has far-flung origins

When most people look up at the night sky, they see emptiness. Stars, to be sure, but mostly a black void. When Louis Allamandola, an astrochemist based at NASA’s Ames Research Center in Moffett Field, Calif., looks up, he sees life. Everywhere. Perhaps not life in the literal sense, but its building blocks—materials just like those delivered to Earth via comets or meteorites some 4.5