'It gave me goosebumps': Most powerful gamma ray burst ever detected hid a secret, scientists say

In 2022, scientists spotted a strange signal coming from the most powerful cosmic explosion ever detected.

Now, scientists say they know what made it: matter and antimatter colliding and annihilating each other at 99.9% the speed of light.

The cosmic explosion was a gamma ray burst (GRB), a massive explosion of gamma-ray light that gets unleashed when a massive star collapses into a black hole. As the resulting cosmic behemoth devours matter, some of that matter is hurled in the opposite direction of the growing black hole, forming powerful jets of energy that beam through the dying star's exterior, according to a statement from NASA. 

When those jets aim at Earth, space-based satellites and spacecraft may detect them.

Related: Brightest gamma-ray explosion of all time scrambled Earth's upper atmosphere

The brightest of all-time gaMMA-ray burst on record — nicknamed the BOAT but officially named GRB 221009A — was detected Oct. 9, 2022. At the time, it beamed so many gaMMA rays toward our planet that it saturated all the detectors onboard spacecraft circling Earth, including NASA's Fermi GaMMA-ray Space Telescope. 

As a result, those detectors blinked out during the most intense part of the explosion. After about five minutes, however, the burst subsided and the detectors began working again. At that point, they detected an unusual peak in energy of around 12 million electron volts, which lasted about 40 seconds, according to the statement. For comparison, visible light has an energy of around 2 to 3 electron volts.