A video appearing to show a UFO flying behind a SpaceX capsule has caused a stir online.

Conspiracy theorists were quick to jump on the video, which shows Elon Musk's Dragon capsule spacecraft heading towards the International Space Station, claiming it was proof that aliens exist.

In the footage uploaded by SecureTeam10 and ThirdPhasOfMoon, an unidentified object seems to glide behind the spacecraft as in visible for just a few seconds before it flies out of the camera's range.

Conspiracy theorists were quick to jump on the video, which shows Elon Musk's Dragon capsule spacecraft heading towards the International Space Station with an unidentified object behind it 

The video's description on YouTube claims that the 'large triangular object flying behind the dragon capsule' was 'emitting light in several places, probably it's propulsion system.'  

It then speculates that the UFO could be a 'TR3B' which is, according to OuterPlaces.com a top secret type of experimental spacecraft, which some believe was 'reverse engineered by the US or Russia at some point from a crashed alien ship.' The TR3B has become legendary among conspiracy theorists.