Latest news from Mars is fresh dramatic evidence that water flowed through cracks in underground rock millions of years ago, providing possible habitats for a simple form of life.

The fractures are revealed in photos of Candor Chasma, part of the planet’s own “grand canyon”, Valles Marineris, which is six times deeper than the Earth’s Grand Canyon.

Patterns in the rock, which used to lie several miles underground, were revealed in images taken last year by the most powerful camera ever sent to Mars.

They showed that mineral deposits had been left along the cracks. Experts say the liquid flows may have produced conditions to support the existence of microbial life.

The rock patterns in Candor Chasma were noticed by Chris Okubo, a geologist at the University of Arizona. He said: “What caught my eye was the bleaching or lack of dark material along the fracture. That is a sign of mineral alteration by fluids that moved through those joints.”

Okubo said light tones, or “haloes”, reminded him of similar effects he had observed in sandstone on geology field trips to Utah. He added: “The most likely origin for these features is that minerals that were dissolved in water came out of solution and became part of the rock material lining the fractures. Another possibility is that the circulating fluid was a gas, which may or may not have included water vapour in its composition.”

Professor Alfred McEwen, principal investigator for the HiRise camera, said the results showed the value of observations from orbit identifying areas for study by possible future lander missions.

He added: “The alteration along fractures, concentrated by the underground fluids, marks locations where we can expect to find key information about chemical and perhaps biologic processes in a subsurface environment that may have been habitable.”

The HiRise instrument is watching the Red Planet from aboard Mars Reconnaissance Orbiter which can detect an object the size of a coffee table. The new discovery is published in the latest issue of Science.

I told back in December how Nasa had discovered evidence that liquid water is still flowing on the surface of Mars today. And last month there came evidence that Martian seas are today locked underground including a frozen sea at Elysium, near the planet’s equator.
Photo: Nasa/JPL/Univ. of Arizona

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