NASA scientists warn that Earth could be at a higher risk of an asteroid impact than previously thought. They found new evidence that Earth has been hit by asteroids before that were ten times more powerful than a nuclear bomb, MailOnline reports.
The warning came from James Garvin, the Goddard Space Flight Center Chief Scientist, who found four asteroids that could be so strong that they blew off part of Earth's atmosphere over one million years ago.
Earth Has Three Times Higher Risk of an Asteroid Impact Than Previously Thought, NASA Warns
3D Map Reveals Asteroid Impacts in the Past Were So Powerful It Caused Extinction
To evaluate four impact craters, Garvin and his colleagues examined data from various Earth-observing satellites. They observed broader rings surrounding the spots, concluding that prior researchers had misinterpreted their findings.
If the new data is right, the repercussions would be equivalent to an explosion ten times the size of the greatest nuclear weapon ever detonated, resulting in global extinction. Garvin presented the findings last week at the Lunar and Planetary Science Conference.
The investigation was undertaken as part of planetary defense research, revealing far more than anyone could have expected. Gavin could map four craters in 3D using new high-resolution data taken over the last million years. Pantasma in Nicaragua, Bosumtwi in Ghana, Iturralde in Bolivia, and Zhamanshin in Kazakhstan were among the locations.
The records reveal that the nine-mile Pantasma crater was caused by an asteroid 800,000 years ago that produced the equivalent of 660,000 megatons when it hit Earth. Garvin's reanalysis showed that the crater is 21 miles wide, and the impact was comparable to 727,000 megatons, enough to 'tear off part of the Earth's atmosphere and spread impact glasses widely.'
Additionally, Garvin and his colleagues noted that reanalysis of the Bosumtwi (Ghana) topography using the RPS approach reveals an outermost rim of 26.8 km with an inner peak ring (with deep hollow within) of six miles.
But perhaps the Zhamanshin impact feature in Kazakhstan is more bizarre with its 18-mile-wide rim, which is more than twice the recorded data. The Zhamanshin impact feature in Kazakhstan was also noted to be just six miles wide, but reanalysis reveals it is about 18 miles.
Not All Scientists Agree
Unfortunately, Gavin's conclusions are not universally accepted. Planetary dynamicist Bill Bottke from the Southwest Research Institute in Boulder, Colorado, told Science.org that he is suspicious of the findings and would need more evidence to believe them.
According to data, an asteroid or comet 3,280 feet broad or bigger is anticipated to strike Earth every 600,000 to 700,000 years, and if the latest study is true, four have struck our planet in the last million years alone.
Crater researcher Anna Łosiak from the Polish Academy of Sciences also said that the recently discovered 'rims' are not part of the impact site.
She explained that it would be frightening because it would suggest humans do not truly understand what is happening and that a lot of space rocks may come and create a mess in the future.
RELATED ARTICLE: Five Asteroids on Course To Hit Earth; Scientists Identify Several Space Rocks That Could Strike the Planet in the Next Centuries
Check out more news and information on Asteroids in Science Times.
![Sat-Nav in Space: Best Route Between Two Worlds Calculated Using 'Knot Theory' [Study]](https://1721181113.rsc.cdn77.org/data/thumbs/full/53194/258/146/50/40/sat-nav-in-space-best-route-between-two-worlds-calculated-using-knot-theory-study.png)
