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Jan. 12 (UPI) -- High-definition images have revealed the 3D structure of large subsurface ice sheets on Mars, a first. The images were captured using the HiRISE instrument on NASA's Mars Reconnaissance Orbiter and analyzed by scientists at the U.S. Geological Survey. Their analysis revealed new details about the ice deposits' composition, vertical structure and thickness.
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NASA scientists identified eight locations in the mid-latitudes where ice has become exposed on the eroded, pole-facing slopes known as scarps. MRO and its HiRISE instrument targeted the eight sites.
The ice deposits are encased by only a thin layer of ice-cemented rock and dust, beneath which lies mostly pure water ice. The deposits could provide future manned missions to Mars with a steady water supply.
Scientists believe the icy deposits can prove as scientifically useful as ice and sediment cores collected on Earth. The varied layers can offer insights into Mars' geology and climate history.
Early analysis of the newly imaged ice deposits -- described this week in the journal Science -- has already confirmed scientists basic understanding of Mars' climatic past.
"This [research] supports models for snowfall and accumulation in the geologically recent past," Colin Dundas, a researcher with the USGS Astrogeology Science Center, told UPI in an email.
Scientists believe the scarps detailed in the new study are formed by the sublimation process, as exposed ice evaporates into the atmosphere. The process sees the ice move from a solid to a gaseous state, skipping the liquid phase. Over the time, sublimation causes the icy slope to retreat like glaciers, becoming longer and wider.
Scientists knew there were expansive subsurface ice deposits spread across much of Mars. Now, scientists can confirm the deposits feature relatively pure ice within just a few feet of Mars' surface.
While scientists can see some of the ice sheet's layering -- variation in the concentration of dust and sediment in the ice -- researchers won't be able to truly tap the deposits' scientific potential until they drill sample cores.
Mars has plans to send a surface-drilling lander to the Red Planet this year, but the InSight lander will be collecting sediment cores, not ice.
"InSight is planned to land near the equator, far from any known ice deposits," Dundas said.
Scientists will continue to tap the new images for all the science they're worth, but researchers are already thinking about how to learn more. To do so, more hi-res images may be necessary.
"We and the rest of the scientific community will need to understand how this cross-sectional information at our study sites is similar to and different from conditions at other locations where such information is not available," Dundas said.
