A massive fireball dropped over the southern Atlantic Ocean on February 6 but remained unnoticed. The fireball probably exploded roughly 30 kilometers over the ocean, and surprisingly, no one noticed it except for NASA engineers.

The fireball is supposedly the biggest one ever to hit the Earth since February 2013’s Chelyabinsk explosion. The incident took place at around 9 am off the coast of Brazil. The fireball was packed with energy equal to 13,000 tons of TNT. In comparison, the Chelyabinsk explosion brimmed with a groundbreaking energy of 500,000 tons when it crossed the skies of Ural Mountains.

On the basis of the high-altitude impact felt, NASA team estimates that the space rock was about 5-7 meters wide. The rock that led to the Chelyabinsk explosion was roughly 20 meters in width. Considering the numbers, the recent event is apparently a repeat of the Chelyabinsk.

If the incident is explained using notable descriptions, then why the incident remained unnoticed? Astronomer Phil Plait carried out an investigation and made some calculations to explain the event.

A large rock chunk from space can cause a blazing and shattering impact while entering the Earth’s atmosphere. In case the rock is huge, it can enter deep into the atmosphere first before starting to burn. Once it happens, the rock compresses the gas in front of it, raising the temperature of the meteoroid, and ultimately glows.

Thereafter, it can either evaporate or blow off, which causes a slow down or total disappearance. In case the rock is bigger, then it can break when air puts enormous pressure on it. The resultant debris catches fire, and changes into smaller pieces.