The discovery of a piece of land that held water in the past by the researcher Dr. Mary Bourke from Trinity College Dublin, made it a major target in the search of life forms on Mars.
Dr. Bourke did studies on Earth in the Namib desert close to the Walvis Bay, and found crusty arcs of sand cemented by water and minerals on the surfaces of migrating sand dunes by utilizing the photos from a satellite. She gathered other researchers to check the ground and they found that the striations occured when the dunes were chemically cemented by the salts left from the evaporated water.
“On Earth, desert dune fields are periodically flooded by water in areas of fluctuating groundwater, and where lakes, rivers and coasts are found in proximity,” said Bourke. These periodic floods leave tell-tale patterns behind them.”
“Once the material had been cemented, it hardens and remains behind as the dunes continue to migrate downwind.”
With the help of a colleague from the University of Oxford, Professor Heather Viles, they examined close up photos of Mars surface using the Mars Reconnaissance Orbiter.
“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.”
She examined the arctuate striations that were found on Earth too and found fluctuating levels of water in the time when it was migrating across the valley.
The scientists proposed that the water came from an impact that formed the Lucaya Crater, especially if ice existed there.
The high temperature would’ve vaporised the water but they could possibly melt other ice to flow for some time as liquid water.
The waters flowing through the crater could have created the valley and the salts found there. Then the erosion of the wind would have created the strange striations we see today.
Carbonate rocks such as limestone could be created and dissolved by the water, and evidence of their existence there is confirmed through spectroscopy. They would have served as a cement to solidify the sands between the dunes. Combined with the alternation of dry and wet periods would have caused the striations we see in the MRO photos.
“These findings are hugely significant,” said Bourke. “Firstly, the Martian sand dunes show evidence that water may have been active near Mars’ equator — potentially in the not-too-distant past. And secondly, this location is now a potential geological target for detecting past life forms on the Red Planet, which is important to those involved in selecting sites for future missions.”