During the last Ice Age, six to seven million extra square miles of Earth were locked under massive ice sheets...most of it across Canada and the northern United States. Any cosmic impact in that era had a far greater chance of striking ice, not rock. Earlier theories claimed the ice melted over tens of thousands of years, but radiocarbon data compressed that timeline dramatically. Deglaciation wasn’t slow and steady... it was rapid, abrupt, and catastrophic. | The Randall Carlson