In December an incredibly bright meteor exploded over the Bering Sea, and we all missed it. This fireball, as these exceptional events are called, disintegrated roughly 26 kilometers (16 miles) above the ocean. It released a huge amount of energy, an estimated 173 kilotons. That is more than 10 times the energy of the atomic bomb that hit the city and inhabitants of Hiroshima in 1945.
The blast happened on December 18, 2018, at 11.50 UT (midday local time). Given its isolated location, the quick flash only alerted military satellites and was not directly seen by human eyes at all. Still, this was good enough for scientists at NASA to calculate its trajectory, while researchers across the globe discovered that it was also captured by civil satellites.
The trail of smoke and fire left by the bolide was spotted by NASA’s Terra satellite and by a Japanese weather satellite, Himawari-8. Both were able to see the dark trail as well as the yellow-orange cloud produced by the superheating air after the fireball passed through it.
“The bright orange trail is almost vertical, corroborating NASA data that suggests that the meteor entered the atmosphere at a very steep angle,” Dr Simon Proud, from the University of Oxford, said in a statement. "Being able to see this meteor from space really demonstrates the capabilities of the global fleet of satellites, allowing us to see events that would have gone unnoticed in past decades.”
Dr Proud successfully searched the Himawari-8 data for evidence of the fireball. He applied a processing technique he had previously pioneered and he hopes to work out the precise trajectory of the meteor. Knowing that it might be possible to work out the orbital path of this object, the researchers think that they might be able to have more information about the origin of the meteor in the coming weeks.
This approach was previously used to calculate the orbit of the Chelyabinsk meteor that hit Earth in February 2013. This fireball is the most powerful observed since Chelyabinsk, which damaged thousands of buildings in the homonymous Russian town causing non-fatal injuries to over 1,400 people. Given the high-altitude and remoteness of this fireball, it did not pose any threat to people.
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