The stolen flying saucer and the secrets of Area 51

A 17-year-old has been arrested for stealing a model spaceship close to the most famous place on earth for alien sightings.

He was caught on CCTV at the International UFO Museum and Research Center in Roswell, New Mexico.

It's believed he had two accomplices who are still on the loose.

The model was taken on 19 March and was later found in pieces just outside Roswell.

See the CCTV of the theft released by New Mexico Police.

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The International UFO Museum and Research Center is not home to any real UFOs. Instead, it houses literature and memorabilia related to the infamous incident of 1947, when a military spy balloon crashed on a ranch just outside the town.

The local paper at first reported that a "flying disc" had crashed, but the air force issued a press release in response saying it was a weather balloon.

Suggestions of a cover-up didn't come until years later, when a group of UFO enthusiasts got hold of documents related to the crash, which they say prove that the object was actually a spacecraft and that alien bodies were recovered.

Major Jesse Marcel from the Roswell Army Air Field with debris found 75 miles north west of Roswell in June 1947 - it was later proved to be military kit

A new report came out in 1994 which said the wreckage wasn't, in fact, a spaceship or a weather balloon, but US spying equipment used for picking up Russian radio signals.

Despite most of the "aliens" in the photos that appeared at the height of the conspiracy looking suspiciously like something you might find in Toys 'R' Us, the theories are still going strong.

The truth, say the hardcore believers on the darkest corners of the internet, may be found in Area 51, the secretive military base in the Nevada Desert.

Nobody knows what's really in it. But people have a lot of fun guessing. Here are some of the wilder theories.

Crashed UFOs

Some people think that the whole weather balloon/secret spyware story is nothing more than a cover story, and that what really happened when the Roswell craft crashed was that the wreckage, and the aliens that died in the crash, were taken to Area 51 and hidden.

A New York Times article from 1996 features Glenn Campbell, a man who decamped to a trailer near Area 51 to sell maps of the area to tourists, and believes the government might be hiding UFOs there.

Another common belief is that scientists and military engineers on the base examine alien technology for us to copy on Earth. Basically, Snapchat might have been invented in Space. But probably not.

Boyd Bushman holds up a photo of an alien being

Real aliens that are definitely not fake

Just before his death in 2013, a man called Boyd Bushman revealed a collection of photos of "aliens", claiming they were taking during his time working at Area 51 as an employee of Lockheed Martin, an aerospace company. But not everyone is convinced that he ever went to Area 51 or that he worked for the firm.

The aliens in the photos look very similar to a cheap plastic toy. Chris Sereda, who calls himself a "spiritual explorer", reckons the toys were placed in supermarkets by the government after the photos were released as some sort of complicated double bluff.

An alien model on display inside the museum in Roswell

Petite pilots with abnormal heads

In Annie Jacobsen's 2011 book Area 51: An Uncensored History of America's Top Secret Military Base, she claimed that the Roswell craft was the result of an evil plan between the Russian dictator Stalin and a Nazi surgeon.

She says the alien bodies allegedly seen by eyewitnesses after the crash were actually "human guinea pigs that appeared to be children" created as part of a Cold War plot to send the US into a panic over an alien invasion threat.

Nuclear bomb testing and spy planes

The Telegraph reported in 2013 that the CIA had finally acknowledged "strange goings on" at Area 51.

A report was released under the Freedom of Information Act, which described the area as an "Atomic Energy Commission test site", and revealed that the U-2 and Oxcart spy planes were also tested there. Jeffrey Richelson, the researcher who got hold of the documents, suggested that the numerous reported UFO sightings around the base were actually the planes.

A fake moon landing

This one's actually true. National Geographic published a list of facts about Area 51, including the revelation that astronauts tested land rovers and life support equipment at the base before their real mission to the moon.

Apparently, there was also a tennis court and a bowling alley to entertain the employees stationed there - or was it so the aliens could keep fit?

"UFOs are real" but the punctuation is paranormal

Secret railways

Area 51 isn't small - in fact, it's over 23 miles wide. But some conspiracy theorists reckon the real business happens underground.

"A few claim the underground facility has up to 40 levels and that it is attached via underground railways to other sites in Los Alamos, White Sands and Los Angeles," claims darkgovernment.com.

But no-one's ever seen large amounts of concrete and other construction material enter the site.

A gift shop

Reddit user kiver16 did an AMA with his mum's boyfriend, who claims to have been to Area 51. Instead of being concerned with the threat of alien invasion, one poster just wanted to know if they'd be able to pick up a souvenir of their trip to Nevada.

"Area 51 has a gift shop?" Asked Texas_Hog. Kiver16 confirmed that yes, it does, but it's "somewhere outside the gate [and] nothing to do with Area 51."

Could it be our friend Glenn Campbell in his caravan?

And the most elusive things on earth... are they there?

Reddit users have their own ideas about what the US government might be hiding...