Did an extraterrestrial calamity cause extinctions?

Photo © Noel Munford, New Zealand
Photo © Noel Munford, New Zealand

It has long been thought that climate change brought about the extinction of the Paleo-Americans and large animals such as mammoths, mastodons and saber-toothed tigers about 12,900 years ago when the planet stopped emerging from the Ice Age.Instead, it reverted to glacial conditions for another 1500 years. 

Scientists are now more seriously considered what was previously a highly controversial hypothesis – that an extraterrestrial event caused this turn of events. Could a comet have caused such devastation? New evidence indicates that it is very probable.

The consistent discovery of nanodiamonds across North America in sedimentary layers from 12,900 years suggest that only the impact of a comet could have caused their creation.

Nanodiamonds are tiny and are usually only visible with a high tech microscope. Some scientists argue that nanodiamonds could only have been made by a “high-temperature, high pressure event” like the impact of a comet.

Still, not all scientists are on board with this idea. Some contest the hypothesis because there isn’t a crater, and one would think that a comet impacting earth would leave behind a crater. But then again, there aren’t any craters left behind from the dinosaur age either.

Could this extraterrestrial event have caused the nanodiamonds to form? It hasn’t been decided yet but it’s an interesting hypothesis that scientists will continue to explore. While the data indicates that a comet was likely, it will be some time before the hypothesis is proven.