An Irish scientist has found new evidence of flowing water on the surface of Mars.
Dr Colman Gallagher, of the UCD School of Geography, and Open University planetary science researcher Dr Matthew Balme have identified eskers emerging from a degraded glacier in the Phlegra Montes region of Mars.
Dr Gallagher said it was a "coincidence" that their findings were being made public in the same week Nasa announced water was flowing on the surface of Mars.
“We got a tip off last week from Nasa that they were going to make a big announcement. We’re a small operation and we’re not going to compete with Nasa,” he said. “It was probably a good thing because the attention of the media was drawn to Mars over the last few days.”
Eskers, originally an Irish word meaning ridge or elevation, are ridges of sediment similar to a dried-out river bed, which form only by sustained flows of liquid water underneath a glacier.
“They are very common in the Irish landscape,” Dr Gallagher said. “These things form when meltwater flows through conduits, essentially extremely large pipes within glaciers. Eskers are basically the sediment being carried by the meltwater flowing through these conduits. When the flows cease the sediments are deposited.”
Dr Gallagher said the feature formed in the last 150 million years which is a long time in human history but not in geological history. “That is a period of time that is referred to as the Amazonian period on Mars and that is considered to be the current environmental set up on Mars,” he said.
“What we have shown is that for an extremely long time in the Amazonian, water has been produced and to a certain extent stable at the surface.”
The melting of the glaciers which caused the eskers to form was caused by a volcanic source under the ground. They were spotted when photographs sent back by the Mars Reconnaissance Orbiter (MRO) were examined.
The information is published in the academic journal Earth and Planetary Science Letters.
Essential for life
Dr Gallagher has been working on the project for the last 10 years. The presence of water is seen as essential for life as we know it to exist elsewhere in the universe.
“I don’t think we can go beyond the evidence. It doesn’t really tell us anything about life. It tells us that on Mars, in certain places and at certain times, the conditions have been a little more suitable for life if life had evolved in the first place. We don’t know, though, if life ever evolved on Mars.”
On Monday Nasa scientists announced that they have unquestionable evidence of flowing water currently on the surface of Mars.
Satellite images have identified narrow streaks, typically less than 5m wide, that appear on slopes during warm seasons, lengthen, and then fade when conditions become cooler.
Experts have speculated that water might be involved in the formation of the gully-like features, known as recurring slope lineae (RSL), but only now has evidence supporting the theory emerged.
A new high resolution technique has revealed that RSLs at four locations on Mars contain salt minerals that precipitate from briny water.
Mars is much too cold to allow liquid water to flow as it does on Earth, but saline water has a much lower freezing point and it can flow.
Nasa has said, however, it cannot and will not send its Curiosity rover to investigate. It is too far away from the source of the craters involved and the area is too steep.
Nasa has also stated that the rover is not sterile and risks contaminating the wet areas with bugs from Earth which have managed to survive the journey and the harsh conditions on the surface of Mars.