[Beowulf9]

Very interesting article.

If it was a comet it’s still out there. I wonder when it’s due to return?

[Recovering Ex-hippie]

Can we hope for california next?

[Codeflier]

Not sure. Is this implying that the comet itself entered the atmosphere and was destroyed causing massive damage. If so, it will not be back

[jpsb]

Not if the comet exploded in an air bust over Michigan 1,500 years ago.

[katana]

If it impacts the Earth's atmosphere it's no longer "out there", it's "right here". Tunguska in 1908 is an example of what such an event looks like, that one within the 20th century and, fortunately, over one of the least inhabited land areas of the planet.

The disappearance of the "Mound Builder" Culture, named Adena here in Ohio, may have been misdated to the first century AD. Perhaps this later event was the actual cause. The Snake Mound near Chillicothe is particularly unique.