Buried glaciers have been spotted on Mars, offering new hints about how much water may be accessible on the Red Planet and where it is located, researchers said.
Although ice has long been known to exist on Mars, a better understanding of its depth and location could be vital to future human explorers, said the report in the US journal Science.
"Astronauts could essentially just go there with a bucket and a shovel and get all the water they need," said co-author Shane Byrne of the University of Arizona Lunar and Planetary Laboratory in Tucson.
A total of eight ice sites, some as shallow as a few feet (one meter) below the surface, and going as deep as 100 meters or more, have been exposed by erosion. These underground cliffs, or scarps, appear "to be nearly pure ice," said the report.
The discovery was possible due to images and data sent by the Mars Reconnaissance Orbiter (MRO), launched in 2005. The probe's first find of water on Mars was published in Science in 2010.
But now, scientists realize that ice is more widespread than previously thought, said lead author Colin Dundas, a geologist at the US Geological Survey in Flagstaff, Arizona. "There is shallow ground ice under roughly a third of the Martian surface, which records the recent history of Mars," he said.