The Younger Dryas impact hypothesis

The Younger Dryas impact hypothesis (YDIH) is a speculative attempt to explain the onset of the Younger Dryas (YD) cooling at the end of the Last Glacial Period, around 12,900 years ago.The hypothesis is controversial and not widely accepted by relevant experts. A 2018 paper reported the discovery of an impact crater under the Hiawatha Glacier in Greenland of unknown age. Kurt Kjær, the lead author of the paper, speculated that it might date to the Pleistocene (2.58 million to 11,700 years ago), and mentioned a possible connection to the Younger Dryas.