Conspiracy theorists have claimed that a self-portrait taken on Mars by the rover Curiosity.

The theory revolves around a picture released by the American space agency of the $2.5 billion vehicle on the surface of the Red Planet.

The photo was taken by the Mars Hand Lens Imager in October.

curiosity

Above: Curiosity's self portrait


The problem is that in the picture the rover is entirely alone - no arms extended to take the photo, and with no other apparent means of supporting a camera.

For a fairly large number of people online, however, there were only two explanations - either someone (or something) else took the picture, or no one did and it's all a lie.

Well, Nasa has now released a video in which it explains how the picture was taken.

Their response? 'Nope'.

Put simply, it's a composite of 55 images taken via a seven-foot long robotic arm, with the arm painted out with data from other pictures.

"There weren't that many images with the arm in them because of how we positioned the arm," Michael Ravine of Malin Space Systems, who built the camera, told National Geographic.

"It's like if you hold a camera out in front of you with your elbow crooked and shoot--what you'll probably get is your face and top of your body including your shoulder, but most of your arm is out of the frame."

The rover is now moving towards an area of Mars known as Yellowknife Bay, where it hopes to find evidence of life having once existed on the planet.