The asteroid believed to have triggered the end of the dinosaurs’ reign over the globe left a 180-kilometer-wide crater and caused massive climate upheaval. So when scientists discovered a gigantic crater almost nine times the width of Manhattan under Greenland’s ice sheet in 2015, they were left with a question: The newly discovered crater appeared to be 31-kilometers wide and relatively recent — made within the last 100,000 years — so was this asteroid impact catastrophic enough to alter the Earth’s climate?
