text: When confronted with the fiery question of where evidence lies of an impact that only occurred some 12,800 years ago, barely time for a deep breath geologically, the Younger Dryas Impact proponents respond with an extremely weak mumbling about air blasts, asteroid clusters and ice sheet impacts that left no evidence of a large chunk(s) of space debris hitting the Earth. They point out that the Tunguska Impact (called an impact even though it left no crater) was an air-blast at an altitude of 3-6 miles (5-10 km) above Siberia that yielded the equivalent of 3-30 megatons of TNT in explosive force. The skeptics counter with Meteor Crater in Arizona, a beautiful little 1,200 ft (4,000 m) diameter hole 570 ft (170 m) deep made by a meteorite a mere 54 yds (50 m) in diameter that released 10 megatons of energy upon impact. They reasonably expect that a piece or pieces of space debris able to spread ejecta over half of the northern hemisphere, cause a 1,300 year halt in global warming and lead to the extinction of numerous species that had survived for hundreds of thousands of years had to leave some evidence of its arrival behind. The YD proponents then countered with the fact that the northern half of North America was covered with ice sheets and an impact on a 1 to 2 mile thick layer of ice may have mitigated the expected formation of a crater.