built for business. ♪ ♪ bill: we made the is studio look really important for our next guest. is there life on mars? the curiosity rover has detected these organic molecules in the red planet's soil, but we're wondering what it means. corey powell from discover magazine is here to answer that. how are you, sir? the big news is what, what did it find? >> curiosity found methane gas on mars, it's basically swamp mars. where it came from is the big question. methane gas can come from -- bill: cows? >> it can definitely come from cows. it can come from geoare thermal activity -- yee yo thermal --