Ok, so, time for some potentially not great news: Earth may be at a higher risk of an extinction level asteroid impact than previously believed, according to a recent study by James Garvin, chief scientist of NASA’s Goddard Space Flight Center.
The troubling study comes after Garvin and his team used high-resolution satellite imagery to identify large rings around three impact craters and one probable crater, all less than 1 million years old.
So what does this mean? The rings suggest that the craters are much larger than previously estimated, and the impacts were far more violent, potentially resulting in explosions 10 times more powerful than the largest nuclear bomb in history, according to Science.Org.
These impacts, while not as destructive as the one that wiped out the dinosaurs, could have significantly affected the global climate and caused local extinctions–meaning future strikes could do the same.
“It would be in the range of serious crap happening,” said Garvin at the unveiling.
Garvin acknowledges that his team’s extraordinary claims have not been proven and that fieldwork is required to back up their conclusions.
Other impact researchers remain skeptical, including Bill Bottke, a planetary dynamicist at the Southwest Research Institute, who says he wants to see more evidence before believing the new findings.
This is about to get very science-y, so bear with us.
Current estimates of asteroid impact rates are based on analyzing crater sizes and ages on the Moon, as well as studying the size of near-Earth asteroids. Researchers believe that an asteroid or comet 1 kilometer wide or larger hits Earth every 600,000 to 700,000 years.
However, Garvin’s study suggests that four kilometer-sized objects impacted Earth’s continents within the past million years, with potentially up to a dozen total impacts, considering the planet’s water coverage.
Anna Łosiak, a crater researcher at the Polish Academy of Sciences, doubts the ring-like features identified by Garvin’s team are true asteroid crater rims. If they are, she says it would be “very scary” and indicate a lack of understanding of the space rocks that could impact Earth and cause widespread damage.
Garvin’s team used a database of high-resolution satellite imagery from the company Planet, which enabled them to create 3D maps of the four craters. They combined this data with information from NASA’s height-measuring lasers, resulting in maps with 4-meter resolution.
The team then applied an algorithm to search for circular patterns in the topography. In thousands of tests, the algorithm frequently identified rim-like structures much further out than the accepted crater rim.
Some experienced crater scientists do not see the new rims and suggest they could instead be rings of debris ejected by the impacts. Garvin, however, argues that such debris would not be visible after 1 million years of erosion and that the rings indicate large craters on Earth have more variable structures due to high erosion rates.
For Garvin’s findings to gain credibility, more evidence is needed. Researchers must analyze the climate upheaval triggered by the impacts in ice cores, ocean, and lake sediments. Additionally, they should visit the sites of the rings to search for deformed rocks and gravitational variations that would signify a true crater rim.
With the high stakes involved, this hypothesis must be thoroughly tested, says Brandon Johnson, a planetary scientist at Purdue University. Understanding the true risks of deadly asteroid impacts is crucial for humanity’s survival and ensuring the planet’s long-term safety.