Vast quantities of water on Mars renew hopes of detecting past life there

Instruments aboard NASA's Mars Odyssey spacecraft have detected enormous quantities of ice under the Martian surface, scientists said Tuesday -- possibly enough to support manned missions to the red planet.

The National Aeronautics and Space Administration announced in March that the Odyssey had detected what appeared to be frozen water on Mars.

"The amount of water present on Mars is sufficiently large that it can support future human exploration activities," said Bill Feldman, research director of Los Alamos National Laboratory at Los Alamos, New Mexico, where a neutron spectrometer being used to map the Martian surface was developed.

"The subsurface ice detected by Odyssey may represent only the tip of an iceberg frozen under ground," Jim Bell, an astronomer with Cornell University in Ithaca, New York, wrote in a commentary to appear alongside research results in the Friday edition of the magazine Science.

The findings may also guide the selection of future landing and exploration sites on Mars, and may suggest areas to look for evidence of past life, according to astronomers involved in the research.

NASA said the amount of water detected "could fill Lake Michigan twice over." Located in the northern United States, Lake Michigan has a surface area of 57,441 square kilometers (22,178 square miles) and is 281 meters (923 feet) deep.

Analytical studies of surface maps assembled by Odyssey's three main instruments will appear later this week in Science.

The maps indicate that the highest concentration of possible water ice layers may be buried 30 to 60 centimeters below the Martian surface, from the edge of the polar ice caps to mid-latitudes of 60 degrees, researchers said.

If the observations are confirmed, they will help answer a question that has puzzled Mars researchers for years: just where water the water is.

"The results, even after a month of mapping observations, are stunning," wrote Bell.

Launched in April 2001, the Mars Odyssey is equipped with three instruments that made the discoveries possible. One of these is a gamma ray spectrometer capable of detecting 20 different base chemicals, including carbon, silicon, iron, magnesium.

It also includes the neutron spectrometer, which can detect the presence of water and ice at a depth of up to one meter.

The gamma ray spectrometer was on board the Mars Observer but stopped working just three days before the Observer began orbiting Mars in 1993.

"Many Odyssey investigators have been waiting more than 15 years to finally collect these data," Bell noted.

The probe is also carrying a Thermal Emission Imaging System, which is studying the mineral composition of the Martian surface using thermal infrared images.

And it is fitted out with the Mars Radiation Environment Experiment (MARIE), which includes a spectrometer to measure the energy from radiation sources in the Martian environment that could endanger humans in future manned missions.

At a cost of 297 million dollars, the Odyssey mission -- named in honor of the book by Arthur Clarke and Stanley Kubrick's film "2001, A Space Odyssey" -- is considered the resumption of Mars exploration by NASA.

Its predecessors were the Mars Climate Orbiter and the Mars Polar Lander, which crashed into the red planet in 1999.

Here's JPL's version from :
2002 News Releases
Odyssey Finds Water Ice in Abundance Under Mars' Surface
May 28, 2002

Using instruments on NASA's 2001 Mars Odyssey spacecraft, surprised scientists have found enormous quantities of buried treasure lying just under the surface of Mars -- enough water ice to fill Lake Michigan twice over. And that may just be the tip of the iceberg.

Images are available at http://www.jpl.nasa.gov/images/mars and http://mars.jpl.nasa.gov/odyssey.

"This is really amazing. This is the best direct evidence we have of subsurface water ice on Mars. We were hopeful that we could find evidence of ice, but what we have found is much more ice than we ever expected," said Dr. William Boynton, principal investigator for Odyssey's gamma ray spectrometer suite at the University of Arizona, Tucson.

Scientists used Odyssey's gamma ray spectrometer instrument suite to detect hydrogen, which indicated the presence of water ice in the upper meter (three feet) of soil in a large region surrounding the planet's south pole. "It may be better to characterize this layer as dirty ice rather than as dirt containing ice," added Boynton. The detection of hydrogen is based both on the intensity of gamma rays emitted by hydrogen, and by the intensity of neutrons that are affected by hydrogen. The spacecraft's high-energy neutron detector and the neutron spectrometer observed the neutron intensity.

The amount of hydrogen detected indicates 20 to 50 percent ice by mass in the lower layer. Because rock has a greater density than ice, this amount is more than 50 percent water ice by volume. This means that if one heated a full bucket of this ice-rich polar soil it would result in more than half a bucket of water.

The gamma ray spectrometer suite is unique in that it senses the composition below the surface to a depth as great as one meter. By combining the different type of data from the instrument, the team has concluded the hydrogen is not distributed uniformly over the upper meter but is much more concentrated in a lower layer beneath the top-most surface.

The team also found that the hydrogen-rich regions are located in areas that are known to be very cold and where ice should be stable. This relationship between high hydrogen content with regions of predicted ice stability led the team to conclude that the hydrogen is, in fact, in the form of ice. The ice-rich layer is about 60 centimeters (two feet) beneath the surface at 60 degrees south latitude, and gets to within about 30 centimeters (one foot) of the surface at 75 degrees south latitude.

"Mars has surprised us again. The early results from the gamma ray spectrometer team are better than we ever expected," said Dr. R. Stephen Saunders, Odyssey's project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "In a few months, as we get into martian summer in the northern hemisphere, it will be exciting to see what lies beneath the cover of carbon dioxide dry-ice as it disappears."

"The signature of buried hydrogen seen in the south polar area is also seen in the north, but not in the areas close to the pole. This is because the seasonal carbon dioxide (dry ice) frost covers the polar areas in winter. As northern spring approaches, the latest neutron data indicate that the frost is receding, revealing hydrogen-rich soil below," said Dr. William Feldman, principal investigator for the neutron spectrometer at Los Alamos National Laboratories, New Mexico.

"We have suspected for some time that Mars once had large amounts of water near the surface. The big questions we are trying to answer are, 'where did all that water go?' and 'what are the implications for life?' Measuring and mapping the icy soils in the polar regions of Mars, as the Odyssey team has done, is an important piece of this puzzle, but we need to continue searching, perhaps much deeper underground, for what happened to the rest of the water we think Mars once had," said Dr. Jim Garvin, Mars Program Scientist, NASA Headquarters, Washington, D.C.

Another new result from the neutron data is that large areas of Mars at low to middle latitudes contain slightly enhanced amounts of hydrogen, equivalent to several percent water by mass. Interpretation of this finding is ongoing, but the team's preliminary hypothesis is that this relatively small amount of hydrogen is more likely to be chemically bound to the minerals in the soil, than to be in the form of water ice.

JPL manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. Investigators at Arizona State University, Tempe; the University of Arizona, Tucson; and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories which provided the neutron spectrometer. Lockheed Martin Astronautics, Denver, developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Additional information about the 2001 Mars Odyssey and the gamma-ray spectrometer is available on the Internet at: http://mars.jpl.nasa.gov/odyssey/ and http://grs.lpl.arizona.edu.

Evidence Indicates Water on Mars
Tue May 28,10:42 AM ET
By PAUL RECER, AP Science Writer

WASHINGTON (AP) - Mars may have vast deposits of frozen water just beneath its dusty red surface, boosting the possibility of life on the Red Planet and perhaps providing a source for drinking water and rocket fuel for future exploration, researchers report.

In three studies appearing this week in the journal Science, researchers say remote sensing data from the Mars Odyssey spacecraft suggest that large deposits of water ice are buried just one to two feet below the planet's surface.

Instruments aboard the spacecraft which measure the flux of gamma rays and neutrons detected a strong signature for the presence of hydrogen, a sign for dense deposits of water ice.

The ice is covered by a thin layer of dust and broken rock, the researchers say, but the signals suggest that 20 to 35 percent of the icy layer is water, filling the pores the soil.

Earlier studies had shown strong evidence that Mars was once covered with water. The planet has valleys, gullies and channels, characteristic marks of the flow of water. This lead to speculation about how a planet so covered with water could lose its oceans. The new studies suggest that the water drained downward until it was trapped as ice just below the protective layer of soil.

The presence of vast stores of water could simplify exploration of Mars. Astronauts could use the water to drink or to grow crops in shelters. The water could also be split apart chemically, providing oxygen and hydrogen for rocket propellant.

Proof that water is common on Mars also strengthens speculation that the planet could harbor some microbial life forms. Water is considered essential for the evolution of life and some scientists believe they have evidence, from a Martian rock, that the planet once had life.

Jim Bell of the Department of Astronomy, Cornell University, said in Science that locating the subsurface water could guide Martian explorers in the selection of landing sites.

Bell called the discovery, coming just a month after the orbiting Mars Odyssey craft began its mapping mission, "stunning."

I found this small article from AP via Yahoo, NY Times also has a story. American news organizations are not giving this story much play. I guess they think we Americans find Martian discoveries a bore?

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