Ice on Mars’s North and South Poles

Using Tools on NASA’s Mars Odyssey spacecraft 2001, scientists have been surprised to find enormous amounts of buried ice on Mars’s north and south poles. Enough ice water to fill Lake Michigan twice. And that can only be the tip of the iceberg.

“This is really great,” says William Boynton of the University of Arizona. “This is the best direct evidence we have of subsurface water ice on Mars. What we have found is much more ice than we ever expected.”, he added.

mars soil hydrogen
In this map of a false color of Mars the soil is enriched with hydrogen indicated by dark blue. Source: The neutron spectrometer aboard NASA’s 2001 Mars Odyssey spacecraft.

“It may be better to characterize this layer as dirty ice rather than as dirt containing ice,” says Boynton. The amount of hydrogen detected corresponds to 20% to 50% of ice by mass in the lower layer. Because the rock has a density greater than ice, this amount is more than 50 percent of ice volume per cent. This means that if you have a bucket full of this ice-rich polar background that would result in more than half a bucket of heated liquid water.
William Feldman, chief investigator of GRS the Los Alamos National Laboratories Neutron spectrometer, points out that “the signature of buried hydrogen seen in the south polar area has also been seen in the north, but not in the areas near the pole.” That’s because polar North is dropping below a seasonal layer of icy (dry) carbon dioxide. “As the North spring approaches, the last neutron data show that the monarch is revealing a recurring, rich, hydrogen soil.”

martian poles

Above: in these false-colored maps of the Martian poles, deep blue gives the soil enriched by hydrogen. The South pole is surrounded by icy terai. The Arctic also contains water ice, but it is hidden at the moment by a low winter of carbon dioxide frosts.

“We have suspected for some time that Mars once had large amounts of water near the surface,” says Mars program scientist Jim Garvin at NASA headquarters. But where did water go? And what are the implications for life on Mars? “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.”

Another new result of neutron data is that large parts of Mars in low-mid latitudes slightly improve the amount of hydrogen, are equivalent to containing the different percentage of water mass. The interpretation of this finding is in progress, but the equipment for the design hypothesis is that this relatively small amount of hydrogen is more likely to be chemically linked to minerals in the soil, than in the form of ice.

“Mars has surprised us again. The early results from the gamma ray spectrometer team are better than we ever expected”, says Stephen Saunders, Odyssey’s project scientist at NASA’s Jet Propulsion Laboratory.