A recent spate of UFO sightings around the world has believers in a frenzy, but even the inside scoop from a former astronaut is not enough to sway the sceptics.
Yesterday, aliens popped up in the news again as NASA sought to distance itself from former Apollo 14 astronaut Edgar Mitchell who claimed extra-terrestrials have been coming to visit for decades.
Dr Mitchell, 77, said governments have been covering it up for 60 years.
"I've been in military and intelligence circles, who know that beneath the surface of what has been public knowledge, yes - we have been visited. Reading the papers recently, it's been happening quite a bit," he said.
Dr Mitchell's former bosses were quick to distance themselves from the renewed buzz: "NASA does not track UFOs. NASA is not involved in any sort of cover up about alien life on this planet or anywhere in the universe," the agency said.
But the Australian Skeptics were not impressed by what Dr Mitchell - or anyone else - thought they saw. Skeptic spokesman Barry Williams said today the truth is closer to home: it's all in your head, and you're wrong.
"We love mysteries and we love solving them, just look at how popular crime fiction and crime TV shows are," Mr Williams said. "The brain needs to find answers, it can't stand not knowing, so it comes to an explanation and quite often it's wrong."
Pictures of UFOs
Mr Williams said the UFO explanation is "ready made" after decades of articles, books and movies about alien life. "Two hundred years ago, when nothing of human construction had ever flown, people thought things in the sky were angels or demons.
The sightings
British tabloid The Sun has been leading the UFO charge in the UK, with almost daily sightings being reported. One story includes a photograph of an object in the sky near a mini tornado, while on June 20, a police helicopter apparently chased a UFO in the sky above Cardiff.
The Daily Telegraph reports that a few weeks ago, a UFO spotter at Nowra on the New South Wales south coast reported seeing a military helicopter following a "rounded triangle shape, about the size of a helicopter without tail or rotor blades" across a golf course.
Around the same time, residents of a small town in the Northern Territory reported being terrified by four unidentified flying objects, while in early June an elderly couple on an NT highway said their car was "dive-bombed" by a UFO.
In March, police in Queensland received several reports of an object glowing orange that streaked across the sky. Whatever it was, it was never found and nor was there any evidence that it hit the ground.
Sydney Observatory astronomy educator Mel Hulbert said it was probably a type of meteor known as a bolide and that a rock falls to Earth every two hours, but volunteers at UFO Research Queensland reckon aliens like visiting the sunshine state because of its natural wonders, like the Great Barrier Reef.
The answers
Mr Williams said the more likely explanation was that people were seeing our planetary neighbours, not inter-stellar visitors.
He said Venus is the most common object mistaken for alien aircraft, followed by Jupiter and Saturn which "can look very bright in the sky at different times."
"Most of us live in cities or in towns and don't look at the sky very often," he said. "A flock of birds flying in formation and all turning at once can be mistaken for a UFO. In the right light and from the right angle it can look like a flash of metal."
Mr Williams said the problem is that despite all the UFO sightings around the world, no one has produced any concrete evidence that aliens are visiting Earth.
"We live in a vast, vast universe, which the human mind not capable of comprehending. The thought that this one planet in the whole galaxy is the only one to produce life is a fairly daunting thought," said Mr Williams.
"It's fairly reasonable to speculate about life, but the huge chain of evidence between that and aliens coming to visit just isn't there."
