Alien hunters regularly find what they claim is evidence of ancient statues and ruins on Mars in Nasa images taken by its rovers and space probes.

There is also a well established conspiracy theory that this alleged alien civilisation was wiped out by a nuclear war that destroyed the atmosphere of the planet.

But, space experts have spent decades studying the surface of the Red Planet, but there has so far been no firm proof of any life ever evolving there, let alone intelligent forms like humans.

And, NASA, and other experts deny finding any evidence of even the most simplistic lifeforms yet on Mars, despite sending various rovers and space probes to explore the Martian surface.