The nearest planet of the Solar System to Earth has fascinated the astronomers for hundreds of years.
For some aspects it is similar to Earth. Its day lasts 25 hours and it has got volcanoes, valleys and ice caps that expand or withdraw according to the seasons.
Billion years ago Mars also, had an atmosphere, which could have allowed some sort of life. Dry and tortuous valleys furrowing its surface suggest that rivers flowed there, once.
Nevertheless, in the course of time the atmosphere vanished in the space and the planet cooled down.
Nowadays Mars is a frozen desert.
