Scientists have detected layers of water ice under the surface of Mars.
The discovery does not only add significant details to what humans know about the Red Planet’s geologic history. It may also shape the human colonization of Mars in the future, especially in terms of getting water supply for manned missions.
"This is a new window into ground ice on Mars," said Colin Dundas, who is a geologist from the U.S. Geological Survey and also the person who co-detected the layers of ice.
Mars Has Water Reserves Under Its Surface
Researchers have theorized for a long time that Mars had reserves of water locked under its surface. NASA’s Odyssey mission had scanned Mars from orbit in 2002 and spotted indications of shallow groundwater present at high altitudes. Later, NASA’s Phoenix mission dug up water ice in 2008, at the site of its landing, close to the planet’s north pole.
NASA’s Mars Reconnaissance Orbiter also helped scientists find a buried ice sheet at the mid-latitudes of Mars in 2016. The site was found to contain a volume of water equivalent to that of Lake Superior.
Until now, however, scientists have struggled to find out the accessibility and extent of the subsurface ice layers on Mars. The new study by Dundas and his team addresses this very issue and was published in the journal Science on Jan. 11.
The Red Planet’s Geological Features
The discovery of bands of ice, which are present between 3 and 6 feet under the Martian surface, support the theory that the mid-latitudes of Mars saw large snowfalls periodically millions of years ago. At that point in time, the Red Planet was tilted at a steeper angle on its axis in comparison to what can be seen today.
Bethany Ehlmann, a planetary scientist at Caltech, explained that the new Mars images capture the subsurface ice, which earlier theories had predicted. She also added that the new findings may help researchers to core the ice to get a record of the Red Planet’s recent climate change, similarly to how it is done for Earth.
How The Discovery Could Help Future Human Colonization Of Mars
Future manned missions to Mars, which could land in the planet’s mid-latitudes one day, would have to depend on the local resources to extract water by either mining it from the ice deposits or baking it out off hydrated minerals.
The discovery of ice sheets just a few feet beneath the surface will make ice mining efficient and address the important requirement of slaking thirst. This is a crucial step for successful manned missions and future human colonization.
"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 Shane Byrne, planetary scientist and coauthor of the study.
"Here we have what we think is almost pure water ice buried just below the surface. You can go out with a bucket and shovel and just collect as much water as you need. I think it's sort of a game-changer," Byrne added.