Alien enthusiasts claim to have spotted three huge 'alien portals' below the International Space Station.
A bizarre video has been posted on YouTube, showing three mysterious circular shapes flying below the space station.
While the uploaders believe the shapes could be extraterrestrial, critics have claimed that they are simply clouds.
The video was posted to YouTube by Third Phase of the Moon, a channel that regularly posts videos it claims show signs of aliens.
The footage was originally shot by Nasa from the International Space Station, and shows three white ringed shapes below the station.
In the video, a spokesperson for Third Phase of the Moon says: 'We've got three strange anomalies drifting downwards just above the Earth's atmosphere.
'Is this something extraterrestrial?'
The channel owners describe the mysterious objects as 'smoke rings' that 'seem to be drifting.'
They said: 'I'm not sure these are just anomalous clouds - there's no other ones in the hemisphere.