In February 2009 Google Earth released the first version of Google Mars, an opportunity for everyone to be able to observe the surface of the red planet up close.
However, within weeks Google was accused of censoring the images to hide something.
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In response, Google said the images were provided by NASA.
Then, in 2015, an online video gained international attention. It was purported to show evidence of an entire city on Mars.
So, could it be possible that NASA are hiding alien buildings on Mars?
NASA's official records show that Mars' atmosphere contains 95% carbon dioxide - they say this is hazardous and makes it impossible for the planet to support complex life.
But evidence dating as far back at 1971 suggests maybe it can support life.
A video by Sandra Elena Andrade implies that life on Mars has advanced to the building of structures, beacons and even cities.
UFOligists claim these subjects have been censored from photos by NASA.
NASA has also been accused of deleting data from the Mars Curiosity Rover and replacing photos with blurred sand.
Even former employees have made allegations of tampering to keep the existence of alien life secret.
NASA is a publicly funded organisation which is constantly looking for additional donations - what else would increase public interest more than the possibility of alien life on Mars?