The largest fireball to streak through the Earth's atmosphere since the Chelyabinsk meteor in 2013 was detected over the Southern Atlantic Ocean on Feb. 6, NASA reports.

The recent meteor was detected about 31 kilometres over the South Atlantic, more than 1,000 kilometres off the coast of southern Brazil, NASA reported on its Fireball and Bolide Reports website.

It was travelling at more than 14 kilometres per second, and its energy on impact was equivalent to about 13,000 tonnes of TNT, NASA said. That's slightly less energy than the atomic bomb dropped on Hiroshima during the Second World War. The Hiroshima device exploded with an energy equivalent to 15,000 tonnes of TNT.

Ron Baalke, a scientist with the Near Earth Object program at NASA's Jet Propulsion Laboratory, tweeted that the meteor was the largest fireball detected since Chelyabinsk — a meteor that injured more than 1,100 people and caused more than $30 million damage when it exploded over Russia on Feb. 15, 2013.

A large fireball - the largest since Cheylabinsk - was detected 31km over the South Atlantic on Feb 6<a href="https://twitter.com/BadAstronomer">@BadAstronomer</a> <a href="https://t.co/auCZYlsxz3">pic.twitter.com/auCZYlsxz3</a> —@RonBaalke

However, 13,000 tonnes is a puny amount of energy compared with the estimated 500,000-tonne energy of the Chelyabinsk meteor, which was thought to be 20 metres in diameter, with a mass of 11,000 tonnes before it exploded.

Phil Plait, a former NASA contractor who now writes Slate's Bad Astronomy blog, estimated that based on its energy, the recent fireball was about five to seven metres across — "the size of large living room, say."

He added that "it would've been a dramatic sight to say the least," but given its location, it's unlikely anyone saw it.

He suggested the meteor was probably detected using satellite observations or atmospheric microphones.