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ExoMars discovers hidden water in Mars’ Grand Canyon

on 17 December 2021

The ESA-Roscosmos ExoMars Trace Gas Orbiter has spotted significant amounts of water at the heart of Mars’ canyon system, Valles Marineris.

The water, which is hidden beneath Mars’ surface, was found by the Trace Gas Orbiter (TGO)’s FREND instrument, which is mapping the hydrogen – a very likely measure of water content – in the uppermost metre of Mars’ soil.

While water is known to exist on Mars, most is found in the planet’s cold polar regions as ice. Water ice is not found exposed at the surface near the equator, as temperatures here are not cold enough for exposed water ice to be stable.

Missions including ESA’s Mars Express have hunted for near-surface water – as ice covering dust grains in the soil, or locked up in minerals – at lower latitudes of Mars, and found small amounts. However, such studies have only explored the very surface of the planet; deeper water stores could exist, covered by dust. 

The water-rich area is about the size of the Netherlands and overlaps with the deep valleys of Candor Chaos, part of the canyon system considered promising in our hunt for water on Mars.

As most future missions to Mars plan to land at lower latitudes, locating such a reservoir of water here is an exciting prospect for future exploration.

The finding also makes Valles Marineris an even more promising target for future human exploration missions to the planet. The largest canyon in the Solar System, Valles Marineris is arguably Mars’ most dramatic landscape, and a feature that is often compared to Earth’s Grand Canyon – despite being some ten times longer and five times deeper.

More details here.

Image credit: ESA/DLR/FU Berlin (G. Neukum), CC BY-SA 3.0 IGO