Fireball '2nd only to Chelyabinsk meteor' explodes unseen over Atlantic

© Denis Balibouse
The largest meteor since the one that exploded over the Russian city of Chelyabinsk in 2013 burned up over the open ocean some 1,000 kilometers from the Brazilian coast on February 6, NASA reports.

An extraterrestrial body allegedly the size of a large living room, about 5 to 7 meters across, released energy equivalent to 13,000 tons of TNT, which is 40 times less than the Chelyabinsk phenomenon. The object entered the atmosphere before exploding at approximately 30km above the Atlantic. It couldn`t be observed from the ground as it fell too far away from any populated area unlike the Chelyabinsk meteor, which hit the city with over 1 million dwellers, damaging nearly 3,000 building and causing multiple injuries.

“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,” American astronomer Phil Plait wrote in the Slate’s Bad Astronomy blog. 

The data on the explosion, which became publicly available only two weeks after the incident occurred, is still too scarce to draw any extensive conclusions about its scale and the method NASA had employed to detect the meteor. Plait suggests the scientists might use either seismic monitors to spot the sound wave from the explosion or atmospheric microphones which caught an infrasound from the blast.

On average, 100 tons of meteor debris fall onto the Earth every day, Plait notes, however, they cause little to no damage. Many of the pieces are too small to cause any impact. The majority of the bigger objects disintegrate at speeds of 10 to 100 km per second, at which rocky debris burn up before reaching the ground.

“The increase in surface area means more heating and glowing, then those pieces break up and get smaller, and you get a runaway cascade,” explains the researcher. If the process of disintegration goes too quickly, then people can observe an “explosion,” which is in fact a result of conversion of the kinetic energy into light and heat.

Events of the scale similar to the February 6 explosion occur several times per year, but people are mostly unaware of them as the debris lands in the ocean. 

Although casualties from meteors are extremely rare, it was reported that an Indian man was killed by a fireball’s debris as a flying object struck the campus of a private engineering college in the south Indian state of Tamil Nadu this month.

The victim was reportedly thrown some 6 meters (19 feet) in the air by the impact before he was pronounced dead in the hospital.

The 2013 Chelyabinsk incident caused damage to hundreds of buildings, injuries inflicted mainly by the flying glass from smashed windows led to hospitalization of 50 people with 1,200 more receiving medical attention. However, no deaths were reported.

In general, a person’s odds of being killed by a celestial body impact in a lifetime are estimated to be between 1 in 700,000 and 1 in 250 million.