Have alien hunters found a door on planet Mercury?

Alien hunters believe they have discovered a door on the Mercury which could be an entrance to the planet.

Scott C Waring at UFO Sightings Daily first spotted the object in 2012.

SEE ALSO: Is this a piece of an ancient UFO?

SEE ALSO: Giant glowing UFO stuns thousands in Japan

The rectangular shape appears in a photo taken by NASA.

But YouTube footage shared by SecureTeam10 shows that it may be a monolith.

According to the Daily Mail, Tyler Glockner from SecureTeam10 uploaded the video and said: "I took a really good look, it became clear to me that this is not an entrance at all. In fact, it's something much more magnificent.

"This is a shadow ... where is the shadow coming from?"

"That my friends, is this large, long rectangular object, monolith-looking structure towering up above the surface."

The video has been viewed over 290,000 times.