13 thousand years ago, the Earth experienced a period of rapid warming. Glaciers retreated, the climate became milder, which facilitated the migration of people to new territories. And then, literally overnight, it all changed. Temperatures in the northern hemisphere dropped sharply, bringing glaciers back. Although the new glaciation did not last long, it led to a number of significant consequences. It was during this period that most of the North American megafauna became extinct, and the Clovis human culture also disappeared.
For a long time, the prevailing opinion was that the cooling was caused by the ingress of water masses into the ocean from the giant lakes formed during the melting of glaciers, which disrupted the circulation of global currents. But sometime in 2006, a theory emerged that a rather large asteroid that exploded in the sky over North America was to blame. Traditionally, the scientific community is not very fond of attributing climatic shifts to cosmic catastrophes, so this theory initially did not enjoy much support. But gradually there was more and more evidence that a body actually fell in North America at that time. So the theory began to be taken seriously.
And now, there was more evidence in favor of the asteroid version. Researchers have analyzed sedimentary deposits at a number of sites scattered throughout North America. In most of them, an abnormally high concentration of platinum is observed in the layer corresponding to the time of a sharp climate change 13 thousand years ago.
Here one can draw obvious analogies with sedimentary layers about 65 - 66 million years old - anomalous concentration of iridium is observed in them. This element is rarely found in the earth's crust, but many asteroids are rich in it - as is probably the one that left behind a 180-kilometer crater in the Yucatan Peninsula.
The situation with platinum is similar to iridium. Well, given the fact that traces of platinum were found in sedimentary layers dated from this period and on other continents, a very definite picture is emerging. Of course, even this data is unlikely to end the controversy over whether the asteroid could have caused a climate shift or if it was just a coincidence. But I think that the very fact of the visit of the space guest for 13 thousand years can be considered practically confirmed.