Photo: Cross-section of subterranean ice captured by NASA’s HiRISE camera
Images from an orbiting NASA spacecraft have revealed several sites with huge ice deposits near the Martian surface exposed on steep slopes, said a research published on Thursday.
While of ice on Mars isn’t news – scientists already knew that about a third of the surface of Mars contains shallow ground ice and that its poles harbour major ice deposits – the new find is about thick underground ice sheets exposed along slopes up to 100 yards (meters) tall at the planet’s middle latitudes.
The deposits were found at seven geological formations called scarps, with slopes up to 55 degrees, in the southern hemisphere and one in the northern hemisphere.
The deposits begin at depths as shallow as one meter and extend upwards of 100 meters into the planet. The researchers don’t estimate the quantity of ice present, but they do note that the amount of ice near the surface is likely more extensive than the few locations where it’s exposed. And what’s more, the ice looks pure.
“It was surprising to find ice exposed at the surface at these places. In the mid-latitudes, it’s normally covered by a blanket of dust or regolith (loose bits of rock atop a layer of bedrock),” said research geologist Colin Dundas of the US Geological Survey’s Astrogeology Science Center in Flagstaff, Arizona, who led the study.
The researchers used images from NASA’s Mars Reconnaissance Orbiter, which has studied the Martian atmosphere and terrain since 2006, including the history of apparent water flows on or near the surface.
The findings showed that more ice than previously known may be available for use as water to support future robotic or human exploration missions, perhaps even the establishment of a permanent Mars base. The water could be used for drinking and potentially conversion into oxygen to breathe.
“Humans need water wherever they go, and it’s very heavy to carry with you. Previous ideas for extracting human-usable water from Mars were to pull it from the very dry atmosphere or to break down water-containing rocks,” said planetary scientist Shane Byrne of the University of Arizona Lunar and Planetary Laboratory, a co-author of the study in the journal Science.
However, the ice deposits are still away from the preferred locations for mission to Mars. The eight sites Dundas and his colleagues observed were all located at upper mid-latitudes, between 55 and 60 degrees north or south of the equator, where temperatures can drop extremely low. Most Mars missions, at present, restrict their landing sites to within 30 degrees of the equator.