Sydney, September 29 (ANI): New reports indicate that the NASA Viking 2 probe, which landed on Mars in 1976, may have come within centimeters of finding water three decades before it was eventually found.
According to a report in ABC News, the finding could result in scientists re-evaluating data collected by the spacecraft, which was sent to look for signs of life on the red planet.
"A lot of people think there isn't life on Mars because there wasn't any water on Mars. Our experiment was a definite positive response for life, but a lot of people have claimed that it was a false positive for a variety of reasons. One of the reasons was because there wasn't any water found," said retired Viking scientist Dr Patricia Straat.
Scientists announced last week that NASA's sharp-eyed Mars Reconnaissance Orbiter (MRO) found ice in five freshly made impact craters, several very close to Viking 2's landing site in an equatorial region known as Utopia Planitia.
The MRO images lead scientists to believe that a widespread layer of ice is buried about 25 centimetres beneath the planet's surface.
"Every indication is that this is forming a broad, continuous sheet underneath the surface. We have five separate impact sites all showing more or less the same thing," said MRO scientist Assistant Professor Shane Byrne of the University of Arizona in Tucson.
"It means that Mars had a more humid atmosphere in the recent past, perhaps 10,000 years or so ago," he added.
The ice sheet is believed to extend from the North Pole to about halfway to the equator, a lower latitude than scientists expected, given the Martian climate.
Scientists estimate that it is about a metre or so thick.
MRO has not yet been able to find ice in the southern latitudes, though scientists suspect an ice sheet exists there as well.
"The kind of scientifically heart-breaking aspect of this work is that these craters are located very close to the Viking 2 landing site, (which) dug a trench about 10 to 15 centimetres deep," said Selby Cull, an MRO science team member at Washington University in St Louis.
"If Viking 2 had just been able to dig down a few more inches it would have hit ice," she said.
"We would have liked to have had that information about Mars for the last 30 years. I don't know how that would have changed our perspective, but it certainly would have," she added. (ANI)