Source More than half a million people have pledged to "storm" Area 51 to establish once and for all whether the US government is hiding evidence of the existence of aliens. The secretive 4,000-square-mile post at Edwards Air Force Base in the Nevada desert has long been at the forefront of alien conspiracy theories. Believers maintain that it is used to store captured UFOs or alien remains and technology. The US government categorically denies the existence of such artifacts. Around 500,000 people have now signed a Facebook campaign called “Storm Area 51: They can’t stop us all” which suggests they mass outside Area 51 on September 20. "We can move faster than their bullets,” the organisers said. "Let's see them aliens." The idea, posted by a popular figure in the video game world, stated as a joke, but was propelled by the enduring fascination with Area 51. A spokeswoman for the US Air Force said they were aware of the Facebook campaign. Perhaps not seeing the joke, she added: "It [Area 51] is is an open training range for the US Air Force, and we would discourage anyone from trying to come into the area where we train American armed forces. "The US Air Force always stands ready to protect America and its assets." Signs around Area 51 make clear that intruders will face "deadly force." Seth Shostak, senior astronomer at the SETI Institute in California, which pursues the search for extra-terrestrial life, said: "Area 51, as a rationale in support of visiting aliens, is an argument from ignorance." Area 51 was first used by the US government in the 1950s to test the U2 spy plane, because of its remote location. The government refused to even acknowledge it existed until 2013, and it continues to be sued for testing sensitive aircraft. In 2017 there as renewed enthusiasm among conspiracy theorists when the Pentagon confirmed it had spent $22 million on a secret programme examining UFOs sightings, which it referred to as "anomalous aerospace threats." Luiz Elizondo, the former military intelligence officer who ran the real-life X-Files programme, subsequently told The Daily Telegraph, he had seen convincing top secret evidence of extra-terrestrial craft. He told The Daily Telegraph: "In my opinion, if this was a court of law, we have reached the point of 'beyond reasonable doubt'. I hate to use the term UFO but that's what were looking at. "I think it's pretty clear this is not us, and it's not anyone else, so one has to ask the question where they're from."