UNIDENTIFIED Flying Objects were spotted drifting over Mt Annan on Sunday night, which may be proof we aren't alone in the universe after all.
A Macarthur Chronicle reader has sent in pictures of a mysterious light moving across the sky, which were snapped at 8.30pm on December 1.
The reader, a local business owner who did not wish to be named, said she and her family watched the four UFOs pass over their home.
"They were very high up in the sky, too high for a helicopter and distinctly round and definitely not a plane of any sort. They glided very fast and with no sound," she said.
"The first was a green glowing disc, the shape was very prominent. We watched in amazement as it travelled from Campbelltown directly over the Cascades and towards Camden. It travelled slowly enough for us to watch it the entire time, never lost its colour or shine and the speed was constant."
The reader said there was more action in the sky five minutes later. "Another one showed up, this time white in colour but smaller, and travelled the exact same route.
"We ran around frantically trying to get a camera and shortly afterwards a red disc appeared, this time also small. Shortly after that we saw a white one travel across the sky in another direction."
UFO Paranormal Research Society president Larraine Cilia said there had been plenty of UFO action in the region in the past six months.
"Back in August after one of our meetings, I was standing outside the Campbelltown Arts Centre with five other members and we saw a black triangle with no lights appear in the sky," she said.
"It was very ghostly and moved across the sky, blocking out the stars. We all sketched it afterwards and compared what we had, but it was very unusual and we're not sure what it was."
Macarthur Astronomical Society speaker liaison John Rombi said the object passing over Mt Annan could have been a meteorite or space junk coming into Earth's atmosphere.
"What the reader has described sounds like a meteor, which are coming through the atmosphere all the time," he said.
"The fact it was green points more towards it being a meteor or space junk. However it could even be a spacecraft the reader is unfamiliar with."
Mr Rombi said most people's first instinct when they see something appear in the sky was to call it a UFO.
"As astronomers we can identify the majority of things we see in the sky, but not everyone is this well trained and when they see something like this, their first thought is to call it a UFO."