NASA scientists reveal Earth could be at a higher risk of asteroid impact than previously believed.
The stark warning comes from James Garvin, the Goddard Space Flight Center Chief Scientist, who determined four asteroids strong enough to blow off part of the atmosphere hit over one million years.
Such sizable space rocks are predicted to strike only once every 600,000 to 7000,000 years.
Garvin and his team analyzed data from several Earth-observing satellites to examine four impact craters and identified larger rings around the sites, determining previous work had misread their findings.
If the new data is correct, the impacts would equate to an explosion 10 times more powerful than the largest nuclear bomb in history, resulting in a mass extinction.