A mysterious spike of platinum buried deep in Greenland’s ice has long fueled theories of a catastrophic comet or asteroid strike 12,800 years ago—possibly triggering a sudden return to icy conditions known as the Younger Dryas. But new research points to a far less dramatic, yet still powerful culprit: volcanic eruptions. Scientists found the platinum signal doesn’t match space debris and actually appeared decades after the cooling began, ruling out an impact as the trigger.