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The planet Mars has interested scientists for hundreds of years. 1_______. This sounds surprising, but astronomers say that there could have been lakes, rivers and seas on the surface of the planet. 2_______. In 1877, the Italian astronomer Schiaparelli was looking through his telescope at the planet, when he noticed that there seemed to be a network of canals on the planet. 3_______. When the Americans sent Mariner 4 into space, it sent back 21 photographs, which show that Mars is a cold, lifeless world. Therefore, we can conclude that people could not be living there now, although they might have done so in the past. In 1976, the photographs taken by Viking 1 were examined, and one of them showed a strange pyramid-shaped rock which could be taken for a human face. Was this a trick of the light or evidence that a great civilisation used to exist on the planet? 4_______.
Many believe that life must once have existed on the planet.
David Scott, of the US Geological Survey, believes that The Elysium area on Mars could have had water to a depth of 1500 metres.
His discovery led to the idea that an intelligent civilisation might be living on the planet.
These people might have been building great monuments while we on Earth were still living in caves!