- A gigantic meteor blew up in the Earth's atmosphere with ten times the force of the Hiroshima nuclear bomb in December, but went largely unnoticed until now, according to NASA.
- NASA said that a meteor exploded above the Bering Sea, off the coast of Russia, in December last year.
- Meteors impacts this large are rare on earth, and tend to come only two or three times every 100 years.
A gigantic meteor blew up in the Earth's atmosphere with ten times the force of the Hiroshima nuclear bomb in December, but went largely unnoticed until now, according to NASA.
NASA said it initially missed the fireball because it exploded far from land over the Bering Sea, off the Russian Peninsula, BBC News reported. The US Air Force notified the space program after military satellites picked up the meteor last year.
Lindley Johnson, NASA's planetary defense officer, told the BBC meteors this large are rare, and tend to come only two or three times every 100 years.
The blast, which occurred on December 18, was one of the largest of its kind in the last 30 years, second only to the meteor that exploded over Chelyabinsk, Russia, six years ago. The 2013 fireball was the size of a six-story building and injured about 1,200 people with its impact.
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The latest meteor exploded 15.9 miles (25.6km) above the Earth's surface, and had an impact energy of 173 kilotons, according to the BBC. By comparison, the atomic bomb dropped on the Japanese city of Hiroshima during World War II had an energy of around 15 kilotons.
Kelly Fast, near-Earth objects observations program manager at NASA, told the BBC it had about 40% of the energy release of Chelyabinsk.
"But it was over the Bering Sea so it didn't have the same type of effect or show up in the news," she said. "That's another thing we have in our defense, there's plenty of water on the planet."
Incidents like the one in the Bering Sea have scientists looking for new ways to monitor and predict when a meteor will collide with Earth. A mission concept is currently developing a space-based telescope called NeoCam to support ground-based observatories.
Dr. Amy Mainzer, chief scientist on NeoCam at NASA's Jet Propulsion Laboratory, told the BBC that the telescope could discover asteroids larger than 459 feet (140 meters) from a gravitational point in space.
Without the mission, it could "take us many decades to get there with the existing suite of ground-based surveys," she said.