Mars may have had hot springs

WASHINGTON: A little NASA Mars rover has come across soil that scientists said on Tuesday suggests hot springs may have percolated long ago on the Martian surface, providing an environment conducive to life. The six-wheeled rolling robot Spirit, exploring the expansive Gusev Crater just south of the Martian equator, detected a patch of light-coloured soil that was 90 percent pure silica, an indicator of the past presence of water, they said. Scientists using the rover to glean information about Mars said the discovery is the latest strong piece of evidence that dusty and desolate Mars was once wet and wild.

Wondering whether life on Earth is unique in the cosmos, scientists are eager to know whether Mars was ever habitable, perhaps by microbial life forms. Water is a vital
ingredient for life.

Silica is found widely on Earth in several forms including quartz and opal. It is a common sand component. And it often is deposited in places like hot springs where scalding water interacts with rock. Scientists are offering a couple of explanations for the Martian silica. One is that it may have resulted from the interaction of soil with acid vapours produced eons ago by volcanic activity in the presence of water.

Another more intriguing theory, they said, is that the silica was spawned in hot springs like those seen at  Montana and Idaho. The fact that the soil was 90 percent silica got the scientists’ attention. Scientists have amassed a lot of evidence of large deposits of water ice at the Martian poles and signs of limited surface water elsewhere.

Since one of Spirits’ wheels no longer rotates, the rover scuffs up the ground as it rolls through the mix of hard rock and loose soil on the surface. Venturing through a low range of hills inside the crater, it scraped up and exposed some bright soil that turned out to be the silica.