While the world is divided over whether 'that dress ' is blue and black , or white and gold , Nasa has been involved in a colour controversy of its own . This time the debate involves Mars – the so-called 'red planet ' – which conspiracy theorists believe is in fact more blue and green . They argue the space agency has manipulated the colour of images from Mars to appear red , orange and pink , in what they claim is an attempt to mask life on the planet . Scroll down for video . The debate has raged since the 1970s when Nasa 's Viking 1 lander became the first spacecraft to touch down on the red planet/ Its initial images revealed what appeared to be a blue sky ( right ) , but in reality Nasa says the planet has a red/orange sky . On the left is a processed image of what Nasa believes Mars to look like . The sky on Earth is blue because of a phenomenon known as 'Rayleigh scattering ' , in which blue particles of light are scattered around by the atmosphere . On Mars , the reverse effect takes place . The dust in the atmosphere scatters the red particles of light , makes the sky appear red . Nasa claims the sky appeared blue because Viking 's filtered images still had to be calibrated with the right colour balance . The debate has raged since the 1970s when Nasa 's Viking 1 lander became the first spacecraft to touch down on the red planet , according to a report by Alan Boyle in NBC News . Its initial images revealed what appeared to be a blue sky , similar to that seen on Earth , raising hopes that there may be Martian life . Viking team member Carl Sagan announced at a press conference soon after : 'Despite the impression on these images , the sky is not blue ... The sky is in fact pink . ' The sky on Earth is blue because of a phenomenon known as 'Rayleigh scattering ' , in which blue particles of light are scattered around by the atmosphere . On Mars , the reverse effect takes place . The dust in the atmosphere scatters the red particles of light , makes the sky also appear red . Nasa claims the sky appeared blue in the first Martian images because Viking 's filtered photographs still had to be calibrated with the right colour balance . Nasa sometimes uses different filters to depict Mars . The left image shows Mars as seen by the Hubble Space Telescope in July , 2001 . Centre is Mars as seens by the Hubble Space Telescope in March , 1997 . On the right is the red planet as seen by the Mars Global Surveyor in February , 2006 . The left version is the raw , unprocessed view as it is received directly from Mars . The centre is a guess of the 'natural ' colour that humans would see if they visited Mars . The right version shows the result of white-balancing , which interprets the scene as if it were viewed under Earthlike lighting conditions . But not everyone is convinced . Ron Levin , a researcher at Lockheed Martin stated in areport : 'An excess of red is found on all of the Martian blue and green panels . 'Such extreme illuminations are shown to be incompatible with the grey panels . 'It appears that the true raw image data have been modified prior to publication to convert the blue and green pixels to grey , rendering a grossly changed image . ' Conspiracy theorists have made wilder claims , with one writing : 'The images were falsely reddened to make it appear there was no life , no green algae or lichen on the plane . ' Today both the Opportunity and Curiosity rover have patches of colour attached to their instruments that are used in to adjust the reflected colour to a true likeness . Is this what Mars really looks like ? A mosaic from Nasa 's Curiosity rover shows Mount Sharp in raw colour . Nasa says raw colour is similar to the way the scene would look 'in a typical smart-phone camera photo ' Pictured is the same scene after it has been given a white-balanced colour adjustment that turns the sky blue . Nasa sometimes does this to simulate Earth-like lighting , making it easier to analyse the geology . As a result , pictures of Mars are usually altered to provide a red and pink tinge caused by the iron-heavy dust that fills the atmosphere . But even Nasa admits this is n't an exact science . Colour balance is a highly subjective and no two spacecraft use the same exact filters . As well as this , people often perceive colours differently – as shown by the famous black and blue dress . To clear up the debate , Nasa usually releases a number of different types of Mars imagery , which include the raw file , unprocessed colour pictures and true-colour versions . To add to the confusion , the Curiosity rover recently found that the interior of Mars ' rock 'Telegraph Peak ' is in fact blue/grey . To add to the confusion , the Curiosity rover recently found that the interior of Mars ' rock 'Telegraph Peak ' is in fact blue/grey . Colour balance is a highly subjective and no two spacecraft use the same exact filters.As well as this , people often perceive colours differently – as shown by the famous black and blue dress .
In 1976 mercury 's mercury spacecraft sent back an image of Mars with blue skies . the claimed image had yet to be calibrated with right colour balance . Some conspiracy theorists have criticized Nasa 's calibration methods . it admits it is n't an exact science and often uses different methods .