Key Points
- Melburnians noticed a mysterious ball of light shoot across the city's sky on Monday.
- The Australian Space Agency investigated the phenomenon, after residents suggested it could be a meteor.
- The agency has since confirmed it was likely the remnants of a Russian Soyuz-2 rocket re-entering the atmosphere.
The Australian Space Agency has said a mystery fireball that appeared in Melbourne's sky on Monday night was likely the remnants of a Russian rocket.
Residents reported hearing a loud boom followed by what seemed to be an earthquake-like aftershock, before the object shot across the city’s sky.
Meteor shower or space junk over Melbourne?
Geoscience Australia identified seismic signals in the city’s northwest, which usually relate to earthquakes.
The stunning light display had residents confused as to whether it was a meteor shower or space junk.
"Incredible sight in sky over the SE Melbourne tonight #meteor #sonicboom #SpaceX Falcon 9 debris?" posted one resident.
Another account, Exploring Melbourne, posted: "What an amazing sight over Melbourne. Space junk or meteor, it was spectacular to see it."
The Australian Space Agency investigates
On Tuesday, the Australian Space Agency determined the flashes of light seen were likely from the remnants of a Russian Soyuz-2 rocket re-entering the Earth’s atmosphere.
The agency said the rocket had launched from the Plesetsk Cosmodrome in Russia earlier in the evening.
According to Russian authorities, the launch placed a new global navigation satellite into orbit.
Remnants of the rocket were planned to safely re-enter the atmosphere into the ocean off the southeast coast of Tasmania.
Space junk often confused with meteors
Associate professor Michael Brown from the School of Physics and Astronomy at Monash University said space junk can often be confused with meteors.
He explained that meteors entering Earth's atmosphere are usually far shorter events, as they slam into the atmosphere at over ten kilometres per second.
"As the rocket was travelling at several kilometres every second as it entered the atmosphere, it experienced vast forces that heated and broke up the rocket, producing a spectacular light show," he said.
Brown said a Soyuz rocket had previously re-entered over Melbourne back in 2014, and some of its pieces were later found in rural NSW.
Astronomer Alan Duffy said space junk is easily recognised by a particular colour emitted from the mystery source.
"It was clear that it was something big, as it moved quite slow – suggesting it was rather dense.
"As it burned you could see broken orange fragments, which indicates the material was iron or steel," he said.
"It was one of the most spectacular re-entries that I’ve ever seen."
