(Daily Mail) -- Nasa has spoken out on the controversy surrounding a strange 'glow' spotted on Mars - and says it is either a shiny rock or a glitch in the Curiosity rover's camera.
UFO blogger Scott Waring claimed that the new photograph taken by the rover suggests there are intelligent creatures living underground.
However, Nasa says it has now investigated the image, and found it is simply a trick of the light.
'One possibility is that the light is the glint from a rock surface reflecting the sun,' a Nasa spokesperson told MailOnline.
'When these images were taken each day, the sun was in the same direction as the bright spot, west-northwest from the rover, and relatively low in the sky.
'The rover science team is also looking at the possibility that the bright spots could be caused by cosmic rays striking the camera's detector.'
Nasa's engineers believe the glow may have been caused by sunlight reaching the camera's sensors through a vent hole in the camera housing.
The agency says this has happened previously on other cameras on Curiosity and other Mars rovers when the geometry of the incoming sunlight relative to the camera is precisely aligned.
Nasa also revealed the glitches are commonplace.
'Among the thousands of images received from Curiosity, ones with bright spots show up nearly every week.'