Sand Dune Compositions On Mars Indicate A Watery History

Scientists from Dublin’s Trinity College have detected a patch of land in an ancient valley on Mars that seems to have been flooded by water not too far back in history. By identifying the spot, the research team has highlighted a prime target on the Red Planet to search for past alien life forms.

“On Earth, desert dune fields are periodically flooded by water in areas of fluctuating groundwater, and where coasts, rivers and lakes are found in proximity. These periodic floods leave tell-tale patterns behind them,” Mary Bourke from Dublin’s Trinity College said, according to The Irish Times. “You can imagine our excitement when we scanned satellite images of an area on Mars and saw this same patterned calling card, suggesting that water had been present in the relatively recent past.”

The research team has observed these patterns before during a remote sensing study of the Namib Desert in Namibia. The patterns, called arcuate striations, were seen on the surface between migrating sand dunes. Further study showed that the arcuate striations occurred due to dune sediments that were geochemically cemented by salts that evaporating groundwater left behind. Later, the dune sediments became comparatively immobile.

On the basis of their findings in Namibia, the researchers have hypothesized that a similar situation on Mars also implies fluctuating levels of salty groundwater at a time when the dunes were actively moving down the valley. The scientists worked with data specifically from the Proctor Crater area on the southern highlands of Mars.

Furthermore, according to the researchers, the findings and subsequent implications are huge because the sand dunes on the Red Planet show evidence that there may have been active water near the equator of Mars in the not too distant past. This location is now important for finding past life forms on the planet.