When NASA’s Mars Global Surveyor (MGS) sent back images of the potato shaped moon Phobos, alien enthusiasts were excited to see what looks like a small white cube on the surface of the Martian satellite.

Images from MGS, which was launched in 1996, shows what appears to be an artificial monolith on Phobos.

A white box-type building is seemingly partially submerged in the moon with dirt building up on all sides.

And astronaut Buzz Aldrin has acknowledged the strange ‘base’ in the Martian moon.

Dr Aldrin said: “We should visit the moons of Mars. There’s a monolith there – a very unusual structure on this little potato shaped object that goes around Mars once every seven hours. 

“When people find out about that they are going to say, ‘Who put that there?”

Some claim the entirety of Phobos is artificial and allege it is hollow and used as an alien base.

Alien hunting webiste UFO Sightings Daily said: “Evidence Phobos is artificial: 1st: Phobos is at such a low orbit to Mars it should crash, but its doesn't. 2nd: Phobos changes speed, it accelerates and slows down…impossible unless it has its own propulsion.”

However, there is no solid evidence that Phobos is hollow and scientists have attempted to explain the strange cube anomaly.

Yisrael Spinoza, from the University of Arizona’s Lunar and Planetary Laboratory department, said it is a completely natural phenomenon and that you would find similar structures here on Earth.

He said: “There are lots of rectangular boulders on Earth and Mars and other planets. 

“Layering from rock deposition combined with tectonic fractures creates right-angle planes of weakness such that rectangular blocks tend to weather out and separate from the bedrock.”