SPACE – We already knew that the gamma ray burst “ GRB-221009A » was the most powerful explosion ever observed in space. But we were not yet aware of its effects on our planet… A study published in the journal Nature communication This Tuesday, November 14, partly lifts the veil on this phenomenon that took place two billion light years from Earth. It tells us that this electromagnetic radiation has indeed had an impact on our atmosphere, and worse, that these explosions could damage the ozone layer.
GRB 221009A could therefore be the most impressive gamma-ray burst seen since the dawn of human civilization. For this reason, astronomers gave it a nickname: “BOAT”, for “ Brightest of all time” or “ the brightest ever ” in English. And this colossal explosion is not without consequences.
What is a gamma burst?
To start, you should know that gamma-ray bursts are the most powerful and luminous explosions known in the universe. Scientists have classified them into two categories: short and long. The first last less than a few seconds and are thought to occur when two neutron stars merge, creating a kilonova.
Long bursts last more than two seconds and can be caused by a giant star collapsing on itself, which then forms a black hole. In this case, astronomers think that GRB 221009A belongs to this type of gamma-ray burst.
“ The ozone layer is temporarily destroyed »
But let’s go back to October 9, 2022. On that day, the gamma-ray burst on Earth lasted 800 seconds, at which point the explosion transferred a gigawatt of power to our upper atmosphere. To give you an idea: this is the equivalent of the power of a nuclear reactor.
This was also enough to trigger lightning detectors in India or disrupt long-wave radio communications. But most of all, “Ozone is partially depleted and temporarily destroyed » around planet Earth, as explained New York Times, Pietro Ubertini, astronomer at the National Institute of Astrophysics in Rome and co-author of the study. Luckily the impact only lasted a few minutes and the ozone quickly repaired itself, so that wasn’t the case “nothing serious”explains Doctor Ubertini.
Despite these reassuring words, on October 9 scientists observed for the first time disturbances in the upper part of the ionosphere, this region of the atmosphere between 350 and 950 kilometers above the Earth. A place where the sun’s radiation turns into charged particles that form a strong electric field. “It’s amazing, we can see things happening in deep space that are also affecting Earth”underlines Erik Kuulkers, gamma radiation expert at the European Space Agency (ESA), in a press release.
The closer it is, the more dangerous it is
Disruptions that revive debate in the scientific community “about the consequences of a gamma-ray burst in our Milky Way”explains Mirko Piersanti, researcher at Italy’s University of L’Aquila and lead author of the study published this week.
Indeed, the discovery should help us understand the potential threat of future gamma-ray bursts. Because if this explosion had been closer to us, if it had occurred in our galaxy, the Milky Way, it would most likely have damaged our ozone layer much more seriously. However, it is this layer that protects us from the sun’s UV rays. Without this, life on Earth would not be possible.
But rest assured, there is little chance that such an event will occur during our time on Earth, as this type of gamma-ray burst only occurs about once every 10,000 years.
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