From Comets, Catastrophes, and Earth’s History by W. M. Napier we read ,
“The evidence that an exceptionally large (50-100 km) comet entered a short-period, Earth- crossing orbit during the upper Paleolithic, and underwent a series of disintegrations, now seems compelling. The idea is not new, but it has been strengthened by an accumulation of evidence from radar studies of the interplanetary environment, from the LDEF experiment, from numerical simulations of the Taurid complex meteoroids and ‘asteroids’, and from the latter’s highly significant orbital clustering around Comet Encke.
The disintegration of this massive Taurid Complex progenitor over some tens of thousands of years would yield meteoroid swarms which could easily lead to brief, catastrophic episodes of multiple bombardment by sub-kilometer bolides, and it is tempting to see the event at ∼ 12,900 BP as an instance of this. Whether it actually happened is a matter for Earth scientists, but from the astronomical point of view a meteoroid swarm is a much more probable event than a 4 km comet collision.
Do we have images of disintegrating comets? What does a ‘meteoroid swarm’ look like, anyway? The answer is yes. And comet Schwassmann-Wachmann 3 is a good example of the distribution of fragments we can expect.
And comet Linear is another good example.
So, if we are looking for the planetary scarring of such an event, we should expect to find a lot of smaller craters, instead of one big one.
The simple empirical fact, is that there are literally thousands of craters averaging 100 meters in diameter in Texas, and New Mexico. And I don’t hear anyone talking about them.
Here’s a few places in New Mexico I’d like to visit someday.