Vast Martian dunes hide water reservoirs-scientist

By Paul Hoskins

DUBLIN (Reuters) – 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 on 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 Doctor Mary Bourke of the
Planetary Science Institute in Tucson, Arizona.

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.”

One of those sites is a dune in the southern hemisphere’s
Kaiser Crater which, at 1,558 feet high and 4 miles 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 NASA’s Mars Reconnaissance
Orbiter show cracks, protrusions, unusually steep slopes and
hanging cornices much like those found on dunes in frozen, arid
areas around the 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.”

Bourke accepted 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.