Mars surface an unlikely place for life after 600-million year drought: scientists

Mars may have been arid for more than 600 million years, making it too hostile for any life to survive on the planet's surface, say researchers who have been carrying out the painstaking task of analysing individual particles of Martian soil.

The researchers have spent three years analysing data on Martian soil that was collected during the 2008 NASA Phoenix mission to Mars. Phoenix touched down in the northern arctic region of the planet to search for signs that it was habitable and to analyse ice and soil on the surface.

The results of the soil analysis at the Phoenix site suggest the surface of Mars has been arid for hundreds of millions of years, despite the presence of ice and the fact that previous research has shown that Mars may have had a warmer and wetter period in its earlier history more than three billion years ago.

The team estimated that the soil on Mars had been exposed to liquid water for at most 5,000 years since its formation billions of years ago. They also found that Martian and Moon soil is being formed under the same extremely dry conditions.

Satellite images and previous studies have proven that the soil on Mars is uniform across the planet, which suggests that the results from the team's analysis could be applied to all of Mars. This implies that liquid water has been on the surface of Mars for far too short a time for life to maintain a foothold on the surface.

Dr Tom Pike, from the department of electrical and electronic engineering at Imperial College London, who is lead author on the study published in the journal Geophysical Research Letters, explains, "We found that even though there is an abundance of ice, Mars has been experiencing a super-drought that may well have lasted hundreds of millions of years.