Brightest flash ever disturbed Earth’s atmosphere last year

Final 12 months the brightest flash of sunshine ever seen within the evening sky disturbed Earth’s higher environment in a approach that has by no means earlier than detected earlier than, researchers mentioned on Tuesday.

An enormous burst of gamma rays from an unlimited cosmic explosion round two billion gentle years away arrived at Earth on October 9, 2022, lighting up telescopes around the globe.

Rapidly nicknamed the “BOAT”—for Brightest Of All Time—the flash lasted simply seven minutes however its afterglow was seen to novice astronomers for seven hours.

The flash activated lightning detectors in India and triggered devices that usually research explosions on the sun known as solar flares.

It additionally affected lengthy wave radio communications within the decrease ionosphere, a bit of Earth’s upper atmosphere round 60 to 350 kilometers (37 to 217 miles) above the floor.

The BOAT additionally affected the higher ionosphere—the very first time a gamma-ray burst has been noticed on this part of the environment, a crew of Italian and Chinese language researchers mentioned on Tuesday.

From 350 to 950 kilometers above Earth, close to the sting of the space, the higher ionosphere is the place radiation from the sun turns into charged particles that kind an vital electrical discipline.

Mirko Piersanti, a researcher at Italy’s College of L’Aquila, advised AFP that consultants on this discipline had been debating for 20 years whether or not gamma ray bursts might have any affect on the higher ionosphere.

“I feel we lastly answered the query,” mentioned Piersanti, the lead writer of a brand new research within the journal Nature Communications.

The researchers had been fortunate that the Chinese language–Italian CSES satellite, which has an electrical discipline detector, “was precisely within the zone that was illuminated by the gamma-ray burst” 500 kilometers above Earth within the higher ionosphere, he mentioned.

“We discovered a form within the electrical discipline that had by no means been noticed earlier than,” Piersanti added.

“It’s wonderful,” European Area Company gamma-ray professional Erik Kuulkers mentioned in a press release.

“We will see issues which are taking place in deep space however are additionally affecting Earth.”

Extinction menace?

Piersanti mentioned the analysis would assist scientists perceive the potential threat that different gamma-ray bursts might pose sooner or later.

The worst-case scenario could be if such a robust blast got here from a lot nearer to dwelling—say, inside our personal Milky Way galaxy. That would “utterly erase” Earth’s ozone layer, he mentioned.

This might expose all the pieces on the floor to the complete may of the sun’s ultraviolet radiation, probably wiping out life on Earth.

There has beforehand been hypothesis that previous gamma-ray bursts might have triggered historic mass extinction occasions.

However Piersanti emphasised that a lot stays unknown.

Additionally it is potential that the ionosphere would soak up all of the gamma rays and “nothing would occur” to these of us on the bottom, he defined.

Final 12 months’s gamma-ray burst, formally known as GRB 221009A, is believed to have been brought on by both an enormous dying star exploding right into a supernova, or the beginning of a black hole.

Given its immense energy, it might even have been each—a supernova explosion resulting in the creation of a black hole.

The blast got here from the path of the constellation Sagitta and traveled an estimated 1.9 billion years to achieve Earth.

It’s now 2.4 billion light years away due to the enlargement of the universe.

On common, a couple of gamma-ray-burst reaches Earth each day.

However one with the brightness of the BOAT is estimated to return round as soon as each 10,000 years.

© 2023 AFP