New previously top secret information released by the Ministry of Defence reveals Wiltshire is the West's UFO hotspot.
Dozens of files have now been disclosed under the Freedom of Information Act, containing information on more than 70 UFO sightings in total across the region over the past few years - with 22 sightings in Wiltshire in just eight years.
A fast-moving bright light has been seen over Devizes and a ball of light that changed colour was spotted above MArlborough in February last year.
UFO experts say Britain's longest ley line runs from Dundry, near Bristol, to Salisbury, and think this has something to do with the number of West reports.
The busiest night was on February 20, 2002, when there were eight separate reports across Somerset and Dorset involving a bright blue flash of light in the sky.
In September 2004 there was a sighting of a fast-moving bright light above the village of Iwerne Minster in Dorset, and just eight days later a similar object was seen above Devizes and then Swindon.
The frequency of reports has declined over the years, however. There were 19 in 1999 and 13 the following year, but only five in each of 2003, 2004 and 2006.
Thousands of sightings
But there have been thousands of sightings across Britain since 1999, and the MoD also received reports from other countries, including the US and Sri Lanka.
The files list sightings reported by police officers, air traffic controllers, airline pilots and coastguards. In January 2001, an RAF pilot saw a "mainly stationary" triangular object 25-30 miles over Bath.
In August 2000 a "UFO was seen and filmed onto a VHS tape" in Cheltenham. Other files include a very bright sphere, bigger than a shooting star, above Stonehenge, and "large, silver metal, shining ball, with a dark mist surrounding it, and a blinding light surrounding the mist" at Yeovil.
Despite the drop, each year more than 100 UFO sightings are reported to the MoD, which is required to investigate each one to establish whether UK air space has been compromised.
A spokesman said: "The MoD examines reports solely to establish whether UK airspace may have been compromised by hostile or unauthorised military activity.
"If required, sighting reports are examined with the assistance of the department's air defence experts.
"Unless there is evidence of a potential threat, there is no attempt to identify the nature of each sighting reported."
Correspondence between the MoD and people reporting sightings reveals Whitehall officials remain "totally open-minded" about the existence of aliens from outer space.
The Director of Air Staff said: "The MoD does not have any expertise or role in respect of 'UFO/flying saucer' matters or to the question of the existence or otherwise of extraterrestrial lifeforms, about which it remains totally open-minded.
"To date the MoD knows of no evidence which substantiates the existence of these alleged phenomena. We believe that rational explanations, such as aircraft lights or natural phenomena, could be found for them if resources were diverted for this purpose, but it is not the function of the MoD to provide this kind of aerial identification service.
"It would be an inappropriate use of defence resources if we were to do so."