ScienceDaily (Nov. 21, 2008) — Vast Martian glaciers of water ice under protective blankets of rocky debris persist today at much lower latitudes than any ice previously identified on Mars, says new research using ground-penetrating radar on NASA's Mars Reconnaissance Orbiter.

Because water is one of the primary requirements for life as we know it, finding large new reservoirs of frozen water on Mars is an encouraging sign for scientists searching for life beyond Earth.

The concealed glaciers extend for tens of miles from edges of mountains or cliffs and are up to one-half mile thick. A layer of rocky debris covering the ice may have preserved the glaciers as remnants from an ice sheet covering middle latitudes during a past ice age.

"Altogether, these glaciers almost certainly represent the largest reservoir of water ice on Mars that's not in the polar caps. Just one of the features we examined is three times larger than the city of Los Angeles, and up to one-half-mile thick, and there are many more," said John W. Holt of The University of Texas at Austin's Jackson School of Geosciences, lead author of a report on the radar observations in the Nov. 21 issue of the journal Science.

"In addition to their scientific value, they could be a source of water to support future exploration of Mars," said Holt.