Flash over Kyiv believed to be meteorite

A bright flash seen over Kyiv was probably a meteorite, Ukraine's space agency said Thursday, after officials denied it was a satellite or a Russian missile attack.

Speculation and memes abounded on Ukrainian social media, including jokes that the mysterious flash could have been caused by an alien spacecraft. (AFP)

A bright flash seen over Kyiv was probably a meteorite, Ukraine's space agency said Thursday, after officials denied it was a satellite or a Russian missile attack.

The head of the city's military administration had said that the flash was caused by a NASA satellite returning to Earth.

But a NASA spokesman told AFP that this was not the case as the satellite in question was "still in orbit".

"We cannot identify what it was exactly, but our assumption is that it was a meteorite," Igor Korniyenko, the deputy head of a control centre at Ukraine's national space agency said Thursday.

But he said there was not sufficient data to determine "the exact nature" of what might have caused the flash.

"Our observation devices showed it was a powerful explosion. We recorded it and determined where it took place," he said.

The US space agency had announced earlier this week that a retired 660-pound (300-kilogram) satellite would re-enter the atmosphere some time on Wednesday.

"What exactly it was -- only experts can find out," the military administration's chief Sergiy Popko said on Thursday.

- 'Unknown aerial object' -

But he ruled out that the flash could have been one of the regular Russian missile and drone strikes on the Ukrainian capital since Russia invaded the country in February 2022.

"It was not a missile attack. Our anti-aircraft defence did not deploy its available weapons," Popko said.

He referred to Wednesday's incident as "the fall of an unknown aerial object" and said its glow had "caused excitement and concern among the people of Kyiv".

Speculation and memes abounded on Ukrainian social media, including jokes that the mysterious flash could have been caused by an alien spacecraft.

"While social media is amused by flying saucer memes... please do not use the official symbol of the Air Force to create memes!" the Ukrainian Air Force said.

The Ukrainian Air Force had also said the flash was "related to the fall of a satellite/meteorite."

NASA's RHESSI spacecraft, used to observe solar flares, was launched into low Earth orbit in 2002 and decommissioned in 2018.

In a statement on Monday, NASA said it expected most of the RHESSI spacecraft to burn up as it enters the atmosphere.

"But some components are expected to survive reentry," NASA said, adding that the risk of harm to anyone on Earth was low -- approximately one in 2,467.