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A mysterious noise and light witnessed by hundreds of residents in Melbourne’s north was likely a meteor burning up after entering the Earth’s atmosphere, scientists say.

Residents in Doreen, north-east of Melbourne, reported hearing an explosion and then seeing a bright flash light up the night sky shortly before 9pm on Wednesday.

Aliens, falling construction equipment and exploding meth labs were all floated as possible causes on social media as anxious residents looked for answers.

Victoria Police said they sent officers to patrol the streets of Doreen after receiving numerous reports of an explosion, but were “unable to locate a scene or the source of the noise”.

RMIT space physicist Gail Iles said the most likely cause, based on her investigations, was that a piece of rock had hit the Earth’s atmosphere at high speed, causing it to break up into a collection of smaller pieces.

Iles said she’d devised the theory after determining there had been no warnings issued for rocket bodies or satellites tracking over Victoria and looking at recent launches.

“There was a Starlink launch by SpaceX at about what would have been 9pm our time, but it was a textbook launch, there were no issues with the rocket,” she said.

Iles said there were some meteor showers predicted for this time of year that could have been visible in the Southern Hemisphere.

She said the flash of light followed by sound, indicated a piece of rock “travelling pretty fast” had fragmented.

“The locals were reporting not just one boom but a few and that would indicate that we had several different pieces,” she said.

Australian National University astronomer Brad Tucker said the speed at which the material was travelling created the “sonic boom” when it hit the Earth’s atmosphere.

“It’s essentially all this energy being released in the sky and the meteor, or asteroid fragment, breaking apart,” he told 3AW.

“The brightness and the explosion will all be relative to size, so that kind of gives us a clue that it was probably on the smaller side, the fact that it wasn’t over a larger area.

“It could have been anywhere between 10 centimetres and maybe 30 to 40 centimetres.”

Iles said if any fragments of the asteroid had landed somewhere out in a paddock near Doreen, they’d likely be the size of a golf ball.

“You might not be able to find them because they might just have impacted the earth and then buried themselves underground,” she said.

“If you were to find it immediately after impact, and it hit something, you might find a little crater. It would depend on how big the thing was, how hot it was, how fast it was travelling, and we can really only guess those parameters.”

Iles said we may never get a definitive answer to what caused the sound that rocked Doreen on October 18.

“We can’t say exactly with full confidence. What we can do is eliminate all the things that it could be and just make sure that we’re not missing something obvious, then just go for the most likely option.”

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