The biggest fireball since the meteor that rocked Chelyabinsk in Russia has fallen over the Atlantic, Nasa has revealed.
The event, which happened on February 6 at 13:55 GMT, seems to have gone unnoticed at the time as it burned up about 30km above the ocean, 620 miles off the Brazilian coast.
The energy released as it plunged through the Earth’s atmosphere was equivalent to the detonation of 13,000 tons of TNT. In February 2013, the blast over Chelyabinsk in Russia released the equivalent of 500,000 tonnes of TNT.
Around 1,000 people were injured in that explosion – mostly as result of flying glass from smashed windows. The meteoroid, estimated to be about 10 tons, entered the atmosphere at a speed of at least 33,000mph.
Although the fireball over the Atlantic was still significant, experts played down the impact it would have had if it had occurred over land.
“Events this size aren’t too big a concern,” Phil Plait, an astronomy blogger for Slate, said. “Had it happened over a populated area, it would’ve rattled some windows and probably terrified a lot of people, but I don’t think it would’ve done any real damage.”
He estimated the rock was around five to seven meters wide.
Nasa employee Ron Baalke tweeted the incident after it appeared on the space agency’s Fireball and Bolide Reports web page, which records all significant meteor events.
About 30 small asteroids – between 1m and 20m in size – are estimated to burn up over Earth every year. Most do not affect populated areas because they often fall over the oceans.
In August last year, Nasa was forced to quell rumours that a huge asteroid was due to strike the Earth.
The space agency’s Near-Earth Object Observations Programme said there have been no asteroids or comets observed that would impact Earth anytime in the foreseeable future. It said all known Potentially Hazardous Asteroids have less than a 0.01 per cent chance of impacting Earth in the next 100 years.
“Not a single one of the known objects has any credible chance of hitting our planet over the next century,” said Paul Chodas, manager of Nasa’s Near-Earth Object office at the Jet Propulsion Laboratory in Pasadena, California.
However, an asteroid did fly relatively close to Earth – 499,000km away – on Halloween last year.