Flash in sky over Kyiv caused by satellite reentering atmosphere

A powerful flash in the sky over the Ukrainian capital that triggered an air raid alert late on Wednesday was caused by a Nasa satellite reentering the atmosphere, city authorities said.

“According to preliminary information, this phenomenon was the result of a Nasa space satellite falling to Earth,” the head of Kyiv’s military administration, Serhiy Popko, said on Telegram.

The US space agency had announced earlier this week that a retired 300kg satellite would reenter the atmosphere some time on Wednesday.

The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spacecraft, used to observe solar flares, was launched into low Earth orbit in 2002 and decommissioned in 2018, Nasa said.

Popko said a “bright glow” was observed in the sky over Kyiv at around 10pm (8pm BST).

An air raid alert was activated, Popko said, but “air defence was not in operation”.

Shortly after, the Ukrainian air force said the flash was “related to the fall of a satellite/meteorite”.

Speculation and memes abounded on Ukrainian social media after several channels posted videos showing the powerful flash lighting up the sky over Kyiv.

“While social media is amused by flying saucer memes … please do not use the official symbol of the air force to create memes!” an air force tweet said.

In a statement on Monday, Nasa had said it expected most of the RHESSI spacecraft to burn up as it reentered 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.