Mars is the planet nearest to Earth that we are most likely to explore and send manned missions to. It also is the planet that we have the best chance of finding life on. For both these things water is needed so exploration of Mars by space probes has concentrated on looking for water.
Humans have searched for evidence of water on Mars for many years. In 1895
American astronomer Percival Lowell thought that he had seen canals on the surface of Mars. These were disproved as tricks of the eye. Spacecraft in the 1960’s and 1970’s reported that Mars was very dry. However, spacecraft in the 1970’s to the 1990’s started to report evidence of water, either past or present. The atmosphere of Mars is very thin, only 1% of the Earth’s …show more content…

These blueberries were embedded in layers of rock which indicates that they were deposited in the rock by salty, acidic water.
(taken from New Scientist, January 15 th 2005, p 34 – 38)
• A “razorback” – a ridge of thin, jagged vertical plates of rocks possibly formed when earlier layers of rocks cracked and mineral-laden water seeped through the cracks forming veins. This is an important discovery because it shows that water was on the surface more than once. The layers of sediment needed time to be compressed into rock, and then cracked and the veins of minerals formed.
( taken from http://www.newscientist.com/article.ns?id=dn6178 )
All these point to evidence of salt flats or short-lived lake beds, that have formed, disappeared and reformed again. Tim Parker of NASA’s Jet Propulsion laboratory and Jim Head of Brown University have suggested that part of Mars was once a vast ocean, with cycles of wet and dry.
There are several implications of all these discoveries.
• The presence of water or ice means that life may have evolved on Mars and primitive microbes may be surviving in the soil. The fact that Earth bacteria can survive in dry conditions as spores may mean that Martian bacteria may do the same. Also, bacteria can grow in extreme environments on Earth, even deep down in rock, so such bacteria could be found on Mars.
• NASA would like to send humans to