13,000-Year-Old Cosmic Airburst Triggered ‘Impact Winter’ and Mass Extinction, Research Suggests

New research points to fragments of a comet exploding over North America approximately 13,000 years ago, sparking firestorms and rapid cooling that could have contributed to the extinction of mammoths. Scientists report finding telltale “shocked” quartz grains at classic Clovis sites dating to the Younger Dryas boundary, evidence of intense heat and pressure. This suggests a cosmic airburst triggered widespread fires and an “impact winter,” stressing Ice Age ecosystems and life.

Traces of a Cosmic Blast

According to the study, at three well-known Clovis sites, scientists discovered microscopic “shocked” quartz grains in layers dated to 12,800 years ago. Advanced imaging shows these sand grains contain multiple fractures and even molten silica – signs of extreme heat and pressure.

Such features normally form only during massive explosions. Computer models indicate that a low-altitude airburst from a comet fragment could create the observed shock patterns over a wide area without leaving a crater.

Climate Chaos and Extinctions

Approximately 12,800 years ago, the world suddenly plunged into the Younger Dryas, a 1,000-year mini ice age. One theory suggests that a comet explosion caused this chill. An explosion may have resulted in forest fires and carry soot up the air, the result being a severe form of “impact winter.” This deep freeze, combined with the loss of habitats, would have been disastrous for Ice Age ecosystems.

This may be one of the reasons why mammoths and mastodons, among other megafauna, disappeared at the Younger Dryas boundary.The comet hypothesis remains controversial, however; many scientists prefer alternative explanations, such as massive meltwater surges that disrupted ocean currents and altered the global climate.