The Airbus helicopter bucked wildly in the frigid air hundreds of meters above the Chilean Andes. Every time it heeled over to turn, the helicopter dropped 20 meters, and the jagged peaks below seemed to rush up at Brad Singer through a gaping opening in the copter’s side—the door had been removed to make photography easier. The jolts and the clear path to the ground did not make Singer, a geologist usually based on the flat land around the University of Wisconsin–Madison, feel very secure even though he was strapped into a seat. “It was like being in a big, loud open roller coaster,” he recalls.