Future visitors to Mars in need of water may find large quantities stored away in sand dunes held together with ice, a leading geologist said Monday.
"I think I've discovered evidence for ice in sand dunes on Mars which could be used to produce fuel and help humans to survive on the planet," said Mary Bourke of the Planetary Science Institute in Tucson, Ariz.
While channels and ridges in the Martian landscape indicate that water once flowed across it, and probes have detected ice in the soil, Bourke believes she has found topographical evidence that some of its giant dunes are about 50 percent water.
"My findings do not suggest that there's more water on Mars," she told journalists at the British Association for the Advancement of Science festival in Dublin. "It's identifying a new location that has not been defined before."
The solar system's biggest dune?
One of those sites is a dune in the southern hemisphere's Kaiser Crater which, at 1,558 feet (475 meters) high and 4 miles (6.5 kilometres) wide, Bourke believes could be the solar system's biggest.
Her studies of the Red Planet's terrain reveal dunes with earthly traits. Unlike shifting Saharan desert dunes, but much like those found in Antarctica, they have physical features suggesting something is helping keep their distinctive shapes.
High-resolution images from a NASA orbiter show cracks, protrusions, unusually steep slopes and hanging cornices much like those found on dunes in frozen, arid areas around Earth's South Pole.
"There's evidence to suggest that there's something in the sand dunes on Mars that's sticking them together," Bourke said ahead of a presentation to fellow scientists. "What I am suggesting is that it's water that's doing it."
Other explanations are possible
Bourke acknowledged that there could be other explanations for the sand's ability to hold its shape but said the apparent presence of other features found on our own planet, such as alluvial channels and fans, could have been carved out by meltwater.
Asked whether such sites would be a good starting point for those looking for signs of life, she said the potential was there, given that Antarctica experienced similar climactic conditions as recently as 20,000 years ago.
Life itself was unlikely to have evolved there, however, given that the dunes look to be among the newest features on Mars, having formed as little as 100,000 years ago when Bourke believes the planet may have experienced its last snowfall.