A new study has uncovered the aftermath of a radiation burst from a distant star that collapsed into a black hole
We’re not living inside the plot of a blockbuster sci-fi film (yet), so we don’t get to hear about giant space explosions that often. Last year, though, Earth was on the receiving end of a powerful blast from deep space, and the effects might still be rippling through the upper atmosphere, according to a new study.
The aftermath of the explosion was first picked up by NASA’s Swift satellite on October 9, 2022, as a flash of high-intensity gamma rays. This kind of record-breaking radiation burst is estimated to occur only once every 10,000 years, and is thought to occur when a massive star collapses, turning into a black hole.
“If it had happened much closer, it would have been really bad,” said Brendan O’Connor, an astronomer from George Washington University, at the time. Luckily, it was from a galaxy about 2 billion light-years away, though it was bright enough to be dubbed “BOAT” or the “brightest of all time”, and sent shockwaves through the outer layer of our atmosphere.
Published in Nature Communications, the new study sees researchers from the National Institute of Astrophysics in Rome prove how BOAT – or, to give it its more technical name, GRB 221009A – “deeply impacted” our atmosphere. More specifically, it seemed to change the upper ionosphere, which is located about 500 kilometres above Earth’s surface, right on the edge of space.
What does this mean for us? Well, it’s not something we need to start worrying about any time soon, since layers of Earth’s atmosphere absorb potentially harmful radiation before it reaches the surface. However, disruption to the ionosphere – which can also be caused by events such as solar storms – can have some knock-on effects, like disrupting signals used in everyday communications and navigation systems.
Before this study was published, there had been little investigation of how the BOAT radiation burst affected the top side of the ionosphere, and the process involved combining satellite data with a new, “ad hoc developed” analytical model. The results, which show that the effects were in fact huge, could be vital in helping us to understand the effects of distant explosions on Earth’s atmosphere, and to predict what might happen if one were to happen closer to home. Fingers crossed we won’t need to use that information any time soon.