Another impressive –or better said unprecedented— discovery has been made on Mars. Experts have found enough water ice beneath the Martian surface to fill Lake Superior, our planet’s largest freshwater reservoir. The deposit varies in thickness from about 80 to 170 meters, with a composition which is from 50% to 85% water ice.
The Martian reservoir, is located in the northern hemisphere of the Red Planet, and could serve for the survival of future human colonies. The discovery was made by NASA’s Mars Reconnaissance Orbiter.
Experts analysed part of the Utopia Planitia region in the mid-latitudes of the northern hemisphere of Mars with a radar instrument aboard the orbiter.
Utopia Planitia is a basin with a diameter of about 2,050 miles (3,300 kilometers), resulting from a major impact early in Mars’ history and subsequently filled.
Data analyzes of more than 600 flyovers revealed an icy reservoir with a larger area than the state of New Mexico.
The deposit varies in thickness from about 80 to 170 meters, with a composition which is from 50% to 85% water ice, mixed with powder or larger rock particles.
The so called ‘frozen treasure’ is located halfway between the equator and the pole. The ice water cannot persist on the surface of Mars. It sublimates into water vapor in the thin, dry atmosphere of the planet.
However, the Utopia Planitia deposit is protected from the atmosphere under a terrain of between one and ten meters in thickness. That is why it has managed to hide away from the hazardous climate on the surface.
“This deposit probably formed as snowfall accumulating into an ice sheet mixed with dust during a period in Mars history when the planet’s axis was more tilted than it is today,” said Cassie Stuurman of the Institute for Geophysics at the University of Texas, Austin. She is the lead author of a report in the journal Geophysical Research Letters.
“It’s important to expand what we know about the distribution and quantity of Martian water,” said MRO Deputy Project Scientist Leslie Tamppari of JPL. “We know early Mars had enough liquid water on the surface for rivers and lakes. Where did it go? Much of it left the planet from the top of the atmosphere. Other missions have been examining that process. But there’s also a large quantity that is now underground ice, and we want to keep learning more about that.”
According to NASA, with an axial tilt of 25 degrees, the red planet accumulates massive amounts of water ice at its poles. In cycles that last around 120,000 years, the til varies to nearly twice as much, causing the poles to heat up and drives ice to middle latitudes on the planet.
Scientists estimate that this water source is more accessible than most water ice on Mars.
“This deposit is probably more accessible than most water ice on Mars, because it is at a relatively low latitude and it lies in a flat, smooth area where landing a spacecraft would be easier than at some of the other areas with buried ice,” said Jack Holt of the University of Texas, a co-author of the Utopia paper who is a SHARAD co-investigator and has previously used radar to study Martian ice in buried glaciers and the polar caps.
Joe Levy of the University of Texas, a co-author of the new study, said, “The ice deposits in Utopia Planitia aren’t just an exploration resource, they’re also one of the most accessible climate change records on Mars. We don’t understand fully why ice has built up in some areas of the Martian surface and not in others. Sampling and using this ice with a future mission could help keep astronauts alive, while also helping them unlock the secrets of Martian ice ages.”