Map of shallow subsurface water in Valles Marineris on Mars

On December 15 scientists from Space Research Institute of the Russian Academy of Sciences in Moscow, Russia revealed a discovery of an area with an unusually large amount of hydrogen in the Valles Marineris canyon system on Mars. Assuming the hydrogen is bound into water molecules, as much as 40% of the near-surface material in Candor Chaos region appears to be water. The discovery was made by neutron detector FREND on ESA&Roscosmos's ExoMars Trace Gas Orbiter orbiting Mars since October 2016. FREND is mapping the distribution of hydrogen in the uppermost meter of the planet’s surface. Hydrogen indicates the presence of water, being one of the constituents of the water molecule; it can also indicate water absorbed into the surface, or minerals that were formed in the presence of water.

While water is known to exist on Mars, most is found in the planet’s cold polar regions as ice. Typically water ice is not found exposed at the surface near the equator, as temperatures there are not cold enough for exposed water ice to be stable. Minerals seen in this part of Mars typically contain only a few percent water, much less than is evidenced by these new observations. “We found a central part of Valles Marineris to be packed full of water – far more water than we expected. This is very much like Earth’s permafrost regions, where water ice permanently persists under dry soil because of the constant low temperatures,” told one of the scientists involved in the study.

These are very inspiring discoveries for the future human colonization of Valles Marineris region we have imagined in our speculative Mars Colonization Timeline!

⇧ In the area C up to 40% of the near-surface material appears to be composed of water (by weight).

The most water-rich area in Valles Marineris region is located in Candor Chaos:

HERE is global-scale map of shallow subsurface water distribution on Mars published in 2019.