ESA’s ExoMars Trace Gas Orbiter (TGO) has discovered large amounts of water locked up within Mars’ extensive canyon system, Valles Marineris.
This feature is the largest canyon in the Solar System and can be seen stretching across this frame, overlaid by coloured shading representing the amount of water mixed into the uppermost metre of soil (ranging from low amounts in orange-red to high in purple-blue tones, as measured by TGO’s FREND (Fine Resolution Epithermal Neutron Detector)).
The coloured scale at the bottom of the frame shows the amount of ‘water-equivalent hydrogen’ (WEH) by weight (wt%). As reflected on these scales, the purple contours in the centre of this figure show the most water-rich region. In the area marked with a ‘C’, up to 40% of the near-surface material appears to be composed of water (by weight). The area marked ‘C’ 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.
The underlying grey shading in this image represents surface topography, and is based on data from the Mars Global Surveyor Mars Orbiter Laser Altimeter (MGS/MOLA). The axes around the frame show location (latitude and longitude) on Mars.