New Delhi : Scientists have discovered that some parts of planet Mars may have been flooded by water in the not-so-distant past. The discovery opens up the exciting possibility of finding past life forms on the Red Planet.
A team of researchers from Trinity College Dublin and Oxford University has discovered a patch of land in an ancient valley on Mars that appears to have held water. The area could serve as the prime target to begin searching for evidence of life forms there.
Dr Mary Bourke from Trinity College and her colleague Professor Heather Viles of the University of Oxford published their findings recently in Geophysical Research Letters.
The findings of the team add to the already available evidence from several previous studies that life could exist on the planet. Scientists often link up evidence of water availability with possibility of life forms, though not of the kind found on Earth.
“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. 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", said Dr Burke.
The trinity-Oxford duo, in a remote sensing study of the Namib Desert, had previously noted these patterns -- ‘arcuate striations’ -- on the surface between migrating sand dunes.
Fieldwork subsequently showed that these arcuate striations resulted from dune sediments that had been geochemically cemented by salts left behind by evaporating groundwater. These dune sediments later become relatively immobile, which means they are left behind as the dunes continue to migrate downwind.
“Following our work in Namibia, we hypothesise that on Mars, similar arcuate striations 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", said Dr Burke.
“These findings are hugely significant. 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", she added.