66 million years ago, an asteroid slammed into the earth, specifically the Yucatan Peninsula, in what's now Mexico. It killed almost every living thing on the planet. Boulder geologist Douglas Robertson says, in short, the asteroid kicked up broiling rocks, which then ignited a global firestorm. But some have questioned that theory, arguing that there’s not enough evidence. A new study connects the missing dots. Ryan Warner talks to Douglas Robertson, an emeritus fellow at the Cooperative Institute for Research in Environmental Sciences, about what he recently pieced together.