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NASA scientists reveal that Earth is at greater risk of asteroid impact than previously believed.
The stark warning comes from James Garvin, the Chief Scientist of the Goddard Space Flight Center, who identified four asteroids strong enough to blow away some of the atmosphere that was impacted more than a million years ago.
Such bulky space rocks are predicted to strike only once every 600,000 to 7000,000 years.
Garvin and his team analyzed data from several Earth observation satellites to examine four impact craters and identified larger rings around the sites, finding that previous work had misinterpreted their findings.
If the new data is correct, the impacts would correspond to an explosion 10 times more powerful than the largest nuclear bomb in history, resulting in a mass extinction.
NASA scientists reveal that Earth is at greater risk of asteroid impact than previously believed. Experts reanalyzed four asteroid impact sites that hit more than a million years ago and found that they were not only bigger, but also more powerful
Presenting the findings at the Lunar and Planetary Science Conference last week, Garvin said, “It would be close to serious nonsense.”
The team conducted the study as part of planetary defense research, but discovered more than they could have imagined.
Using new high-resolution images of four craters taken over the past one million years, Gavin was able to map them in 3D.
The locations include Pantasma in Nicaragua, Bosumtwi in Ghana, Iturralde in Bolivia and Zhamanshin in Kazakhstan.
“We have drawn attention to four complex impact craters spanning the past ~1.0 Ma [one million] of the Earth’s history, mostly in tropical regions, with different target rock characteristics presentation.
The papers describe the analysis of Pantasma, which was documented as a nine-mile-wide crater left by an asteroid some 800,000 years ago, and it produced the equivalent of 660,000 megatons when it fell to Earth.
Gavin’s reanalysis claims that the crater is 21 miles (34 km) wide and that the impact was equivalent to 727,000 megatons, enough to “blow some of the Earth’s atmosphere away and spread impact goggles worldwide.”
The papers describe the analysis of Pantasma, which was documented as a nine-mile-wide crater left behind by an asteroid some 800,000 years ago, and it produced the equivalent of 660,000 megatons when it fell to Earth.
“Reanalysis of the topography of Bosumtwi (Ghana) using the RPS method suggests an outer rim of 26.8 km with an inner peak ring (with deep cavity inside) of six miles,” Gavin and his team wrote.
“The perhaps more bizarre Zhamanshin impact feature in Kazakhstan reveals an outer probable rim at 18 miles,” the team wrote while previously documenting it was just seven miles.
The final site, Iturralde in Bolivia, was ten kilometers wide, but new data puts it at 30 kilometers.
However, not everyone agrees with Gavin’s findings.
Bill Bottke, a planetary dynamicist at the Southwest Research Institute in Boulder, Colorado, explained Science.org: ‘I’m skeptical. I want to see a lot more before I believe it.’
Data has predicted that an asteroid or comet 3,280 wide or larger hits Earth every 600,000 to 700,000 years, and if the new study is correct, that means four have hit our planet in the last million years alone.
Anna Łosiak, a crater researcher at the Polish Academy of Sciences, told Science.org she’s not convinced the newly found “edges” are part of the impact site.
“That would be really scary, because it would mean that we don’t understand what’s going on at all — and that there are a lot of space rocks that could come and make a mess,” she said.