A massive comet is believed to have hit Earth close to 13,000 years ago, resulting in a wave of wildfires that affected about 10 percent of our planet's land, and eventually causing what nearly turned out to be another ice age, as clouds of dust blocked out the sun and forced temperatures to drop significantly.
In a study published this week in the Journal of Geology, the researchers explained how the event in question took place shortly after an actual ice age, as early humans were enjoying warmer weather once again. As explained by Phys.org, fireballs suddenly appeared in the sky as the comet made its impact, resulting in dust covering the sky and fires spreading in various parts of the world. The abrupt change in weather caused by the lack of sunlight killed plants and limited food sources, and with ocean currents shifting and glaciers moving forward again after they had previously retreated, the world was plunged into a thousand years or so of near-ice age conditions in what is now known as the Younger Dryas period.
According to study co-author Adrian Melott, professor emeritus of physics and astronomy at the University of Kansas, the scenario is backed up by the discovery of various markers that could point to a 62-mile-wide comet breaking up and crashing to Earth about 12,800 years ago. This caused the aforementioned wildfires that were supposedly more serious than the ones brought on by the "dinosaur-killing" asteroid millions of years prior.
"A number of different chemical signatures – carbon dioxide, nitrate, ammonia, and others – all seem to indicate that an astonishing 10 percent of the Earth's land surface, or about 10 million square kilometers, was consumed by fires," Melott explained in a statement.