There seems to have been something in the air in June.

According to an international group of alien hunters, the number of UFO sightings doubled last month.

The Mutual UFO Network (Mufon) recorded sightings of 1,179 mysterious unexplained crafts in June – an increase from around 600 in the same period last year.

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There appears to have been something in the air in June. According to an international group of alien hunters, the number of UFO sightings doubled last month. High-profile sightings last month included one of a 'flying saucer' UFO which visited Stonehenge

The majority of Mufon's cases are in the US, and the organisation usually receives anywhere from 400 to 700 reports each month.

Around 10 to 20 per cent of these cases turn out to be unidentified when matched up weather phenomenon and man-made objects.

But Roger Marsh, Mufon director of communications, doesn't think this means an impending alien invasion.

'We feel [it] was directly related to the final two episodes of Season 2 of 'Hangar 1: The UFO Files,' he told the alternative news site Open Minds.

The Mutual UFO Network (Mufon) recorded sightings of 1,179 mysterious unexplained crafts in June – an increase from around 600 in the same period last year

Roger Marsh, Mufon director of communications, doesn't think this means an impending alien invasion. 'We feel [it] was directly related to the final two episodes of Season 2 of 'Hangar 1: The UFO Files,'' he told the alternative news site Open Minds

This History Channel documentary took a look at Hangar 1, a facility that houses an archive of more than 70,000 files that have been gathered over a period of nearly 50 years.

The files, maintained by Mufon have recently been opened for investigation.

High-profile sightings last month included one of a 'flying saucer' UFO which visited Stonehenge, according to UFO Sightings Blog.

The site said the UFO was 'black in colour and disc shaped,' and described it as 'medium' size at around 20 to 30 feet (6 to 9 metres) across.

In a separate report a UFO enthusiast claims to have found the wreckage of an alien spaceship in Antarctica.

MAPPING 90 YEARS OF UFO SIGHTINGS Last month a data visualisation expert created a map of the US showing almost 90 years of official UFO sightings (above), including information such as the time of day they are typically noticed in different months. The data also reveals that UFO sightings of fireballs are the most common, while egg-shaped craft are the rarest over time. John Nelson combined census data with statistics compiled between 1925 and 2014 by the National UFO Reporting Centre to make his maps. 'Of course, as is the case for any observation data, there is a strong tendency towards echoing a population map' he wrote on his blog. 'This is certainly the case with this sighting data, as well. In order to visualise the actual sighting phenomenon, I needed to normalise by the underlying population.' To do this, he created a map showing sightings by population density, as well as maps based on more complex calculations to build the most accurate maps he could. Advertisement

Using Google Earth, Valentin Degterev zoomed in on a dark area and says that the shape is a clear sign that it is a crashed UFO.

However, an expert has told MailOnline that it is just a shadow caused by a crevasse, while the blue tinge is bare ice.

Marsh said a very high percentage of the June UFO report surge were historical cases.

'People were watching our show and decided they finally discovered a place where they could report their encounter,' he said.

He added that another explanation for the sightings may be that more people were outside celebrating during the evening hours, and looking up for events such as Memorial Day.

'Some of these are very, very interesting and compelling cases currently under investigation,' he added.