For example, it turns out a strike only 12,800 years ago wiped out cultural development in North America, along with 30+ genera of large animals including horses, camels, and mammoths, with direct effects proven as far as Chile, South Africa, and Syria, and triggering the 1200-year Younger Dryas return to Ice Age conditions.

The fact was hotly disputed by geologists for decades until the smoking-gun layer of platinum-enriched dust was demonstrated.

https://sci-hub.se/10.1086/695703

Google Earth has been instrumental in revealing numerous newly-identified impact craters.

Wholly modern humans are known to have been on earth for hundreds of thousands of years (was 200k, latest evidence 300k). The great mystery is why it took until just a few thousand years ago for civilization to arise and stick. Our ancestors were not less intelligent than us, or less bold. We know people were sailing deliberately out of sight of land 50,000 years ago, because they colonized Australia. We find evidence of common cultural elements spanning thousands of miles and tens of thousands of years.

We don't actually know how old many of the megalithic constructions we inherit were built; we know only that they are at least as old as known people who used them.

There are literally 1M+ square miles of what was rich bottom land during most of that time now deep under the sea. We don't have any idea what was built there.