When Alison Moore looked into the night sky she wondered if it was a bird, a plane, or even a space ship hovering above her home.
Alison Moore filmed the object which was flying above her home
The 26-year-old was amazed when she saw what appeared to be a bright disc floating above her house in Trehafod in the south Wales valleys.
She grabbed her video camera and began filming the "alien ship" in the sky.
But astronomers say the mystery object was probably Venus in the night sky.
The object caught Ms Moore's attention after she got up during the night to see to one of her two daughters.
"I thought it was a shooting star at first because it was so bright," she said.
The family were 'astonished' when they saw the footage
"But when it didn't disappear, I thought it might have been a satellite so I grabbed my video camera for a closer look because I didn't have binoculars and I knew I could zoom in with the camera.
"It was pretty amazing but I couldn't really see how good it was until the next day when I replayed the tapes.
"I could not believe my eyes when I looked at them again.
"It was really strange - the object kept zipping across the screen and the colour changes were absolutely amazing.
"I've never believed in things like flying saucers before but after seeing this I've changed my mind."
Alison was so convinced that she had filmed a UFO that she showed the tapes to her uncle, Alfie Passey.
"I have always thought that these reports of a flying saucer were bull," he said.
"I thought that these things that people had seen was most likely to be a satellite.
"But after seeing the tapes of what Alison had seen, I am absolutely convinced that it was a flying saucer."
South Wales Police have said they received no reports of a flying saucer in the south Wales valleys during the early hours of 4 August.
Dr Mike Reddy from the University of Glamorgan, which runs several astronomy course, said there could be several explanations for the sighting, but said that the planet Venus was probably the most likely reason.
"On the night in question, Venus could be seen quite clearly in the east o the sky during the early hours," he said.
"And it is likely that there would have been a lot of weird colours especially near dawn because of the sun.
"But there are other possible reasons for it - it could have been a weather balloon or a satellite.
"I think the chances of it being a visiting alien are pretty slim though," he added.