Australians were treated to a spectacular light show after a flaming object, believed to be space junk from a Russian booster rocket, streaked across the night sky and lit up social media.
People flocked to Twitter or called radio stations to describe the "amazing" fireball that crossed Australia's eastern states, particularly Melbourne, in a south-west to north-east direction late Thursday.
"It was so fast and then it just slowed and drifted down ... with an enormous trail of light," a listener told Melbourne radio station 3AW.
"You could see as it was coming down close to the ground it seemed to be spluttering and breaking up. It was absolutely fantastic."
Another witness said she saw "an amazing bright light with a really long, white tail with flecks of red".
Some witnesses called the police, fearing the flame, which reportedly lasted up to 20 seconds, was not a meteor or space junk but a crashing plane.
Experts said what they saw was a third-stage Soyuz booster rocket coming down from a Russian launch earlier this week. The Meteor-M #2 spacecraft took off on Tuesday Moscow time.
"This is part of launching rockets—bits and pieces have to come down and we just happened to have one come down quite spectacularly over the top of Australia," Brian Schmidt, a professor of astronomy at the Australian National University, told AFP.
He said it was likely the object was a piece of space junk rather than a meteor as it was travelling slowly and in a "very grazing trajectory across the sky", rather than at a steep angle.
"Those are the things you would expect from something that's orbiting the Earth," added Schmidt, who shared the Nobel Physics Prize with US researchers in 2011.
"This fireball came down exactly on the orbit of this third-stage rocket, which had been predicted to enter the Earth last night Australian time, so it all holds together."
Melbourne-based astronomer Alan Duffy said it was hard to project where the "solid metal pieces" that survived re-entry into the atmosphere would have landed.
"The smallest gust of wind as it falls can send these pieces off by many kilometres, making it unlikely we'll ever know where this ended up," Duffy said.
"Although any farmers in that area might want to watch out for a lump of metal in their fields when ploughing."
Explore further: Australians report flaming object falling from sky