Area 51 memes: The best Twitter posts as 1.2m RSVP to Facebook event to 'raid' restricted US Air Force base

Upwards of one million people have vowed to "Storm Area 51" in September as part of a wacky online bid to "see them Aliens".

The "Storm Area 51" Facebook event hit the headlines after attracting pledges from 1.2 million people desperate to prove alien activity is taking place at the restricted US Air Force base.

Officials have warned that the force "always stands ready to protect America and its assets".

Conspiracy theorists have claimed for years that alien activity takes place at Area 51.

Now the furore surrounding the event has sparked a whole new range of interstellar memes.

Here are some of the best.