A comet may have hit the Earth 56 million years ago, study says

The scientists found hundreds of tiny sand-grain-size tektites like this one, thought to be created when vaporized material from an impact solidified while flying through the air. (Megan Fung)

Million of years in the past, a comet or an asteroid might have slammed into the Earth at an important time in its climatic history, scientists report in a new study.

The extraterrestrial impact that scientists report evidence of occurred about 56 million years ago, approximately 10 million years after the well-known blast from space that killed off all the non-avian dinosaurs. The scientists behind the new discovery based it on clues that they found serendipitously in core samples: microtektites, which are spherical or teardrop-shaped objects that indicate an impact.

"This tells us that there was an extraterrestrial impact at the time this sediment was deposited -- a space rock hit the planet," Morgan Schaller, the first author on the new study and an assistant professor at Rensselaer Polytechnic Institute in New York, said in a statement. "The coincidence of an impact with a major climate change is nothing short of remarkable."

The climate change that occurred millions of years ago— and lasted around 200,000 years— is known as the Paleocene-Eocene Thermal Maximum, and the lead scientist behind the discovery speculated that the comet that they think hit may have been associated with that ancient period of warming.

“A comet impact on its own may have contributed carbon to the atmosphere,” Schaller said in the statement, “but is too small to explain the whole event and more likely acts as a trigger for additional carbon releases from other sources."

Paul Olsen, a professor of Earth and environmental science at Columbia University and an expert on the dramatic events that shaped life on the planet during its history, said he thought the evidence the scientists found was “going to put this whole field on its head!”

“Schaller and his team’s discoveries are real breakthroughs in understand this critical event in Earth History,” Olsen told FoxNews.com in an email.

The study remains controversial. Another scientist, Gerald Dickens of Rice University, pushed back against the findings, saying in a statement that the new study doesn’t  “really explain anything.”

The study suggesting the ancient impact from space was published in the journal Science.

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