Maybe. > The crater was left when an iron asteroid 1.5 kilometers across slammed into Earth, possibly within the past 100,000 years. So there's a chance that

Maybe. > The crater was left when an iron asteroid 1.5 kilometers across slammed into Earth, possibly within the past 100,000 years. So there's a chance that there was an impact in the last 100,000 years. Carlson is saying that there was an impact 12,000 years ago. That's an even smaller chance. I'm not saying Carlson's wrong, but I am saying you're taking a bit of a logical leap here. Further study could put this impact 1M years ago, or even 40,000 years ago, and either option would mean that this is not the impact Carlson is looking for.