Extraterrestrial hunters claim to have found a structure very similar to an Egyptian pyramid in Nasa images of Mars.
ParanormalCrucible, a YouTube channel dedicated to the search for alien lifeforms, has scrutinised video footage from Nasa's unmanned Curiosity Rover space vehicle.
The video of the strange phenomena has gone viral, reaching nearly a quarter of a million views in just a few days.
The "pyramid" is only "car-sized" according to ParanormalCrucible, but others believe this is evidence of intelligent life on Mars, as reported by Daily Express.
Speculation on the nature of the object includes that it could be the tip of a bigger construction, buried under dust on the Red Planet, possibly a grave marker or capstone.
A ParanormalCrucible spokesman said the object's "near perfect design and shape" means it must be "the result of intelligent design and certainly not a trick of light and shadow.
"A remarkable artifact has been found on the red planet by the Mars Curiosity Rover. Due to the size of the object about the scale of a small car I would theorise that the artifact is either the capstone of a much larger pyramid, possibly buried deep beneath the surface or perhaps a marker stone."
Other structures have been spotted on the Red Planet with speculation as to their origins and purpose.
David Martines was scanning Google Mars when he discovered the long white edifice and has even listed the coordinates (71 49'19.73"N 29 33'06.53"W) so others can see it for themselves.
Martines posted a video of the discovery on YouTube which was viewed more than 200,000 times. On the video, he named his discovery 'Bio-Station Alpha.'
"It's very unusual in that it's quite large, it's over 700 feet (210m) long and 150 feet (45m) wide. It looks like it's a cylinder or made up of cylinders. It could be a power station or it could be a biological containment or it could be a glorified garage — hope it's not a weapon."
He added: "I don't know if NASA even knows about this."
However, sceptical scientists discount such discoveries on Mars as Pareidolia - a psychological phenomenon when the eye is tricked by the brain into seeing, faces, animal shapes and other recognisable objects in patterns, rock formations and clouds.