Researchers have found a patch of land in an ancient valley on Mars that they believe is of significant interest in the search for signs of past life forms on the Red Planet.
The site discovered by researchers from Trinity College Dublin was flooded by water in the not-too-distant past, and the suggestion that water was once present at the site means that it may be of particular interest during future missions to the Mars.
“These findings are hugely significant,” said Dr Mary Bourke of Trinity College Dublin. “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.”
The discovery on Mars was made possible by the team from Trinity College’s previous study of the Namib Desert.
In a remote sensing study of the Namib Desert, the researchers had previously noted the same patterns occuring between migrating sand dunes.
Fieldwork subsequently showed that these patterns – described by the searchers as “arcuate striations” – were a consequence of dune sediments being left behind once groundwater had evaporated. These dune sediments later were found to be relatively immobile, which means they are left behind as the dunes continue to migrate downwind.
“On Earth, desert dunefields are periodically flooded by water in areas of fluctuating groundwater, and where lakes, rivers and coasts are found in proximity. These periodic floods leave tell-tale patterns behind them,” said Bourke.
“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 finding on Mars come just weeks after NASA described current plans for a manned mission to Mars as “fragile”, and called for the establishment of a “Marz Czar” or a specialist mission office to adequate preparations were put in place for an unprecedented mission to the Red Planet.
The hypothesis proposed by Trinity College researchers may give fresh impetus to the search for life on Mars.
“Following our work in Namibia, we hypothesise that on Mars, similar arcuate striations [patterns] exposed on the surface between dunes are also indications of fluctuating levels of salty groundwater, during a time when dunes were actively migrating down the valley.”
The researchers’ full findings are available in Geophysical Research Letters.