Odyssey is carrying the Gamma Ray Spectrometer (GRS), built under the direction of Professor William V. Boynton at the University of Arizona Lunar and Planetary Laboratory.

The GRS is a suite of three instruments: the Gamma Subsystem, built by the UA; the Neutron Spectrometer, built by Los Alamos National Laboratory; and the High Energy Neutron Detector, provided by the Russian Aviation and Space Agency, Moscow.

NASA's Mars Odyssey spacecraft began its science mapping mission on Feb. 19, 2001.

After only 10 days, the GRS instruments have made observations of significant quantities of hydrogen within the surface of Mars. The three instruments within the GRS suite have all shown a substantial region located in the southern polar region is very strongly indurated with hydrogen. The hydrogen content is most likely due to substantial quantities of ice, although the amount of ice cannot be quantified yet.

"If this is confirmed, this is fantastic. There is the equivalent of at least several percent water south of 60 degrees latitude", said William Boynton, principal investigator of the GRS instrument suite.

For many years scientists have speculated that near-surface water may exist on Mars. The Gamma Ray Spectrometer instruments have made the first direct measurements that confirm there are significant amounts of hydrogen just beneath the surface of Mars.

For additional information please go to: http://grs.lpl.arizona.edu/results/presscon1/