Mars images reveal 'underground alien bases' UFO believers claim

Others have speculated that the remarkable shapes spotted on the Martian surface are intentionally hidden, perhaps to avoid detection.

It comes after a series of discoveries which alien enthusiasts say suggest signs of life on the planet's surface.

Among the recent discoveries is a mysterious dome structure, picked out in the background of a NASA photo.

While a second shot of the surface of Mars was said to show a face carved into the side of a pyramid.

Scott Waring, who edits the website UFO Sightings Daily, said the new shapes pointed to some sort of underground structure.

The English teacher wrote: "Look closely and you will see the edges of an entrance that takes ships below the surface of Mars.

"This is the location Earth should choose if they want to make a settlement on Mars. This is a location thats already been used and proven effective by aliens."

He added: "Its probably abandoned – just waiting for new owners."

Researcher Marcelo Irazusta is understood to have made the latest discovery before YouTube user Sandra Elena Andrade uploaded his findings.

Grainy scans of the Martian surface made using Google Earth reveal the shapes, which are mostly obscured by what seems an equally unnatural curtain of terrain.

But one unimpressed YouTube user said they could explain away the shapes as being the seams where Google had stitched different scans of the alien world together.

"They are caused by Google Earth algorithm lining up images on the globe and can be found all over Google Earth, Moon and Mars," wrote the commenter.

"If you notice they all occur along the line where two images meet. The top one is darker and has a better resolution to the bottom image.

"You cannot rely on anything you see on Google Earth for true anomaly hunting."

(The Daily Star)