Yesterday the New Horizons probe became the first space craft to reach Pluto. However 50 years ago on July 15th 1965 Mariner 4 became the first space craft to reach Mars.
Although scientists knew that there were no canals or intelligent life on the red planet, many assumed that there would be tundra like plants and lichens there.
The photographs that Mariner 4 sent back although very grainy and of poor quality compared to those that are sent back from modern space craft showed that Mars rather than being covered in simple plant life looked far more hostile and resembled the surface of the Moon.
In one moment in time Mariner 4 changed all the old fashioned romantic views of Mars. Today with rovers on the surface and space craft orbiting Mars, scientists are still trying to answer questions set by the first probe to visit Mars 50 years ago, Mariner 4.