DOZENS of UFOs that the Ministry of Defence cannot explain have been sighted in Wales in the past three years, the release of confidential papers has revealed.
The MoD confirmed that a green, circular object seen hovering in one position over Mumbles in January 2002 was classed as a UFO.
And another bright object seen hovering over West Swansea in January of this year is also being put down as a UFO.
However, Julie Monk of the Ministry of Defence's Directorate of Air Staff made it clear a UFO classification simply meant no rational explanation for a sighting could be found, not that it was extra-terrestrial in origin.
MoD figures show 28 reports of UFO sightings in Wales in the past three years cannot be explained.
The close encounters include a black object hovering over Rhyl, a flying disc over Newport and a spinning craft with legs spotted in the skies above Rhondda.
The figures, released under the Freedom of Information Act, show that there were seven sightings in 2002, eight in 2003, four in 2004 and nine so far this year.
Whitehall-based Mrs Monk said, "The MoD examines any reports of UFOs it receives solely to establish whether what was seen might have some defence significance.
"That is, whether there is any evidence the UK's airspace might have been compromised by an unauthorised aircraft.
"Unless there is evidence of a potential threat to the UK from some external source, and to date no UFO report has revealed such evidence, we do not attempt to identify the precise nature of each sighting."
Mrs Monk said rational explanations could be found for such sightings but it would be "an inappropriate use of defence resources" to go into great depth on each report.
Instead, a number of the reports are simply classed as UFOs and a database of sightings in Wales has now been built up from 2002 onwards.
Because of the large number of reports before 2002, the MoD says the cost of examining, logging and placing them all on a database would be too expensive.
The MoD holds reports of UFOs in Wales going back 25 years.
Cardiff-based UFO researcher Chris Fowler said, "There are credible sightings of unidentified objects in the sky.
"Either these are our craft, which means we've got technology far more powerful than the ones most of us know about, or else they're somebody else's. I don't know more than that."
There have been a number of UFO watching groups in Wales including the Welsh Federation of Independent Ufologists.
The strangest report given to the federation involved a family travelling by car to the Great Orme on November 10, 1997.
They could not account for several "lost" hours when they suddenly became aware of resuming their journey, according to investigator Margaret Fry.
She was told of their account by a friend of the family.
Margaret says the couple and their children where driving on the Bodfair/Landernog road when they found their car engulfed by a purple triangular craft.
The next thing they remember is the purple craft had gone.
She said, "But they could not account for considerable hours of time lost.
"The father was having trouble afterwards with a top molar tooth and he had to go to the dentist.
"A black unknown object fell out while he was at the dentist ... but he had no fillings."
There was a raft of "cigar- shaped object" sightings in Pembrokeshire in the 1970s which prompted an RAF inquiry.
And in January 1974 there were reports a spacecraft "as big as the Albert Hall" landed in the Berwyn Mountains.
Last year, Alison Moore, 26, took footage of a floating disc in the sky above her Trehafod, Rhondda, home.
Although astronomer Mark Griffiths said "it could have been Venus" he said the incident deserved further investigation.