Huge deposit of frozen underground water found on Mars
Scientists using data from NASA's Mars Reconnaissance Orbiter have found a huge reservoir of water frozen beneath a region of cracked and pitted plains of the red planet, which may prove to be a vital
Houston, November 26: The deposit ranges in thickness from about 80 metres to about 170 metres, with a composition that is 50 to 85 per cent water ice, mixed with dust or larger rocky particles.
Scientists using data from NASA's Mars Reconnaissance Orbiter have found a huge reservoir of water frozen beneath a region of cracked and pitted plains of the red planet, which may prove to be a vital resource for astronauts in future.
Researchers examined part of Utopia Planitia region on Mars, in the mid-northern latitudes, with the orbiter's ground-penetrating Shallow Radar (SHARAD) instrument. Analyses of data from more than 600 overhead passes with the onboard radar instrument unveil a deposit more extensive in area than the state of New Mexico, which could hold about as much water as in Lake Superior, largest of the Great Lakes of North America.
The deposit ranges in thickness from about 80 metres to about 170 metres, with a composition that is 50 to 85 per cent water ice, mixed with dust or larger rocky particles. At the latitude of this deposit - about halfway from the equator to the pole - water ice cannot persist on the surface of Mars today.
It sublimes into water vapour in the planet's thin, dry atmosphere. The Utopia deposit is shielded from the atmosphere by a soil covering estimated to be one to 10 metres thick.
"This deposit probably formed as snowfall accumulating into an ice sheet mixed with dust during a period in Mars history when the planet's axis was more tilted than it is today," said Cassie Stuurman from the University of Texas, Austin in the US.
Mars accumulates large amounts of water ice at the poles. In cycles lasting about 120,000 years, the tilt varies to nearly twice that much, heating the poles and driving ice to middle latitudes.
Climate
modeling
and
previous
findings
of
buried,
mid-latitude
ice
indicate
that
frozen
water
accumulates
away
from
the
poles
during
high-tilt
periods.
The
newly
surveyed
ice
deposit
spans
latitudes
from
39
to
49
degrees
within
the
plains.
It
represents
less
than
one
per
cent
of
all
known
water
ice
on
Mars,
but
it
more
than
doubles
the
volume
of
thick,
buried
ice
sheets
known
in
the
northern
plains.
Ice
deposits
close
to
the
surface
are
being
considered
as
a
resource
for
astronauts.
"This deposit is probably more accessible than most water ice on Mars, because it is at a relatively low latitude and it lies in a flat, smooth area where landing a spacecraft would be easier than at some of the other areas with buried ice," said Jack Holt of the University of Texas.
The Utopian water is all frozen now. If there were a melted layer - which would be significant for possibility of life on Mars - it would have been evident in the radar scans.
"Where water ice has been around for a long time, we just don't know whether there could have been enough liquid water at some point for supporting microbial life," Holt said.
Utopia
Planitia
is
a
basin
with
a
diameter
of
about
3,300
kilometres,
resulting
from
a
major
impact
early
in
Mars' history
and
subsequently
filled.
The
study
was
published
in
the
journal
Geophysical
Research
Letters.