What is it? UFO seen in new NASA image of Mars

A genuine NASA image, released by the US space agency this week after it was beamed back from the Curiosity rover droid currently exploring Mars, was found to have the dark disc object in the distant sky.

It was found by UFO investigator Scott C Waring, a USA ex-pat based in Taiwan, who claims he has ruled out it being a smudge on the lens.

He revealed the picture on his website, posting: "This is a UFO from the most recent photos from Curiosity rover this week.

"It has a dark disk and is not an anomaly stuck to the lens.

"I checked other photos from the same camera and it is not there, therefore its not on the lens.

"It is flying in a horizontal position and observing the rover from a distance."