New details have been revealed about the impact of a massive asteroid that hit the US

Scientists have revealed new details about the impact of a massive asteroid that hit the US about 35 million years ago.

The asteroid, between three and five miles wide, created a giant crater 25 miles wide in what is now beneath Chesapeake Bay, centered at the southern end of Northampton County, near Cape Charles, Virginia.

Although slightly smaller than the event that killed the dinosaurs 66 million years ago, researchers expected Earth’s global climate to change in a similar way.

Instead, they found that “our planet seemed to carry on as usual,” said co-author Bridget Wade of University College London (UCL).

In addition, the researchers found that another giant asteroid collided with what is now Russia about 25,000 years ago, disrupting Earth’s climate only for a short period.

That impact left a 60-mile-wide crater – known today as the Popigai Crater – in northern Siberia.

These two asteroid impacts formed the fourth and fifth largest known craters on Earth, and yet they caused no measurable climate changes over the next 150,000 years, the researchers concluded.

“However, our research would not have picked up any shorter-term changes over tens or hundreds of years, as the sampling occurred every 11,000 years,” Wade explains.

‘On a human time scale, these asteroid impacts would be a disaster. They would cause a massive shock wave and tsunami, widespread fires would start, and large amounts of dust would be sent into the air, blocking sunlight.”

The asteroid, between three and five miles wide, created a massive 25-mile crater in what is now beneath Chesapeake Bay, centered at the southern end of Northampton County, near Cape Charles, Virginia.

Evidence of the asteroid’s impacts was found in tiny droplets of silica, which resembled tiny glass spheres.

The formations are created by the intense heat released when the asteroid hits vaporized rocks.

The team deduced what Earth’s climate looked like after the asteroid impact by analyzing carbon and oxygen isotopes in more than 1,500 fossils of coated, single-celled organisms called foraminifera.

These small marine animals lived near the ocean surface or on the sea floor between 35.5 and 35.9 million years ago. served as a record of how warm Earth’s oceans were at that time.

The fossils were found within 10 feet of a rock core drilled from beneath the Gulf of Mexico by the scientific Deep Sea Drilling Project.

The researchers found shifts in isotopes 100,000 years prior to the two asteroid impacts, suggesting that the ocean’s surface warmed 3.6 degrees Fahrenheit, and the deep ocean cooled 1.8 degrees Fahrenheit.

But they found no evidence of any climactic shift around the time of the impacts or afterward.

Another giant asteroid that collided with what is now Russia about 25,000 years ago did not disrupt Earth’s climate for more than a brief period.

“What’s remarkable about our results is that there was no real change after the impact,” Wade said in the paper statement.

“We expected the isotopes to shift in one direction or the other, indicating warmer or cooler water, but that didn’t happen.”

The researchers published their findings in the journal Communication Earth & Environment Today.

The isotope samples collected occurred at intervals of 11,000 years and therefore do not reflect the short-term effects of these massive asteroid impacts, which would have been a “disaster” on a human time scale, Wade said.

For example, the Chicxulub impact caused climate change on a much smaller time scale of less than 25 years. But it was so extreme that it caused the extinction of the dinosaurs.

“So we still need to know what’s coming and fund missions to prevent future collisions,” Wade said.

NASA’s Planetary Defense Coordination Office (PDCO) is developing strategies and protocols to prevent a catastrophic asteroid impact.

Evidence of the asteroid’s impacts was found in tiny droplets of silica, which resembled tiny glass spheres. The formations are created by the intense heat released when the asteroid hits vaporized rocks

The PDCO’s main mission is to find, track and better understand asteroids that could pose a threat to Earth. But it also launched the Double Asteroid Redirection Test (DART) mission in November 2021.

This mission rammed a spacecraft into the near-Earth asteroid Dimorphos to alter its trajectory — a strategy that NASA could one day use to save the planet from an approaching asteroid.

Although Wade and Cheng’s research did not take into account the more immediate effects of the strikes, they did create a more precise timeline of climactic changes, as previous studies used fossil samples over intervals longer than 11,000 years.

Furthermore, using fossils that lived at different depths of the ocean provided a more complete picture of how the oceans responded to the asteroid impacts.

“It was fascinating to read Earth’s climate history through the chemistry preserved in microfossils,” says Cheng.