A significantly large reservoir of “hidden water” or ice has been found in Valles Marineris, Mars’ “Grand Canyon” and the largest canyon in the Solar System—and it’s so near the surface that it could help sustain a future Martian colony.
So say scientists using an instrument on board a satellite orbiting Mars that’s mapping the hydrogen in the uppermost meter of Martian soil.
“Assuming the hydrogen we see is bound into water molecules, as much as 40% of the near-surface material in this region appears to be water,” said Igor Mitrofanov of the Space Research Institute of the Russian Academy of Sciences in Moscow, Russia.
Scientists already know there is water-ice on Mars at its hard-to-reach poles, but the dramatic landscape of Candor Chaos in the Valles Marineris—where the water-ice was found—is at lower, warmer latitudes where Mars missions tend to land.
Candor Chasma, a valley in the northern part of Valles Marineris.
ESA/DLR/FU Berlin (G. Neukum), CC BY-SA 3.0 IGO
Mitrofanov is lead author of the new study published this week in the journal Icarus, which details findings from the Fine Resolution Epithermal Neutron Detector (FREND) neutron telescope on the ESA-Roscosmos ExoMars Trace Gas Orbiter (TGO).
“With TGO we can look down to one metre below this dusty layer and see what’s really going on below Mars’ surface – and, crucially, locate water-rich “oases” that couldn’t be detected with previous instruments,” said Mitrofanov.
The possibly wet area discovered is about the size of the Netherlands, though it could be ice or water that’s chemically bound to other minerals in the Martian surface. “Overall, we think this water more likely exists in the form of ice,” said co-author Alexey Malakhov of the Space Research Institute of the Russian Academy of Sciences.
The science was done by using the telescope to detect neutrons rather than light, with FREND’s higher spatial resolution making the discovery possible. “Neutrons are produced when highly energetic particles known as ‘galactic cosmic rays’ strike Mars; drier soils emit more neutrons than wetter ones, and so we can deduce how much water is in a soil by looking at the neutrons it emits,” said Malakhov.
Artist’s impression of the ExoMars Trace Gas Orbiter at Mars.
ESA/ATG medialab
“We found a central part of Valles Marineris to be packed full of water – far more water than we expected,” he said. “This is very much like Earth’s permafrost regions, where water ice permanently persists under dry soil because of the constant low temperatures.”
The findings make Valles Marineris ripe for future exploration by Mars rovers, though the terrain will be tough to explore.
The ExoMars Trace Gas Orbiter—part one of a two-part mission by the ESA and Roscomos to Mars—has been in orbit of the red planet since 2017. In June 2023 the second part of the mission—the Rosalind Franklin rover—will land on Oxia Planum on the Martian surface.
Wishing you clear skies and wide eyes.
