Science has a mystery on its hands: Did life begin on the surface of the earth, or far, far below it? Ferris Jabr is the author of “Becoming Earth: How Our Planet Came to Life.” He joins host Krys Boyd to discuss the amazing microbes embedded deep within the Earth’s mantle that might be keys to understanding life as we know it on this planet — as well as many others. His companion article in The New York Times Magazine is “The Mysterious, Deep-Dwelling Microbes That Sculpt Our Planet.”