There is plenty of science to suggest that Mars was once home to water. But new research suggests that evidence in clay could have come from lava rather than not lakes -- and that would decrease the odds of life ever existing on the red planet.
Previously, scientists assumed that layers of clay found on Mars were formed either by soil interacting with standing water or from water bubbling up from hydrothermal vents. Either way, the presence of moisture prompted researchers to suggest that life on Mars was a definite possibility.
But new analysis of meteorites suggests that the clays could have formed when water-rich lava cooled. To establish that, researchers from the University of Poitiers in France compared Martian minerals to those formed from cooling lava at the Mururoa Atoll in French Polynesia. The two match up nicely.
Adding weight to the new theory is the fact that the layers of clay on Mars are hundreds of metres thick, so they're more likely to have been formed from lava flows and not soil interacting with water. The research is published in Nature Geoscience.
But the finding doesn't mean that there was never any water on Mars, it just hints that the planet may have been less habitable than previously thought. That means that the finding doesn't rule out the existence of life on Mars, but -- if it's accurate -- just makes it slightly less likely. With any luck, Curiosity will shed a little more light on the situation soon. [Nature via New Scientist]