Planetary researchers utilizing the Fine Resolution Epithermal Neutron Detector (FREND) instrument onboard ESA’s Trace Gas Orbiter (TGO) have discovered proof for very excessive content material of hydrogen within the soil — the imply water equal hydrogen worth as giant as 40.3 wt% — in Candor Chaos, central a part of Valles Marineris.
Mars; the middle of the scene exhibits the complete Valles Marineris canyon system. Image credit score: NASA Goddard Space Flight Center.
“With TGO we can look down to one meter 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,” stated Dr. Igor Mitrofanov, a researcher on the Space Research Institute.
“FREND revealed an area with an unusually large amount of hydrogen in the colossal Valles Marineris canyon system: 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.”
Dr. Mitrofanov and his colleagues analyzed FREND knowledge obtained from May 2018 to February 2021, which mapped the hydrogen content material of Mars’ soil by detecting neutrons quite than gentle.
“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,” stated Dr. Alexey Malakhov, additionally from the Space Research Institute.
“FREND’s unique observing technique brings far higher spatial resolution than previous measurements of this type, enabling us to now see water features that weren’t spotted before.”
“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.”
“This water could be in the form of ice, or water that is chemically bound to other minerals in the soil.”
“However, other observations tell us that minerals seen in this part of Mars typically contain only a few percent water, much less than is evidenced by these new observations.”
Valles Marineris could be seen stretching throughout this body, overlaid by coloured shading representing the quantity of water combined into the uppermost meter of soil (starting from low quantities in orange-red to excessive in purple-blue tones, as measured by TGO’s FREND instrument). The coloured scale on the backside of the body exhibits the quantity of ‘water-equivalent hydrogen’ (WEH) by weight (wt%). As mirrored on these scales, the purple contours within the middle of this determine present probably the most water-rich area. In the world marked with a ‘C,’ as much as 40% of the near-surface materials seems to be composed of water (by weight). The space marked ‘C’ is in regards to the measurement of the Netherlands and overlaps with the deep valleys of Candor Chaos, a part of the canyon system thought of promising in our hunt for water on Mars. The underlying grey shading on this picture represents floor topography, and is predicated on knowledge from the Mars Global Surveyor Mars Orbiter Laser Altimeter (MGS/MOLA). The axes across the body present location (latitude and longitude) on Mars. Image credit score: Mitrofanov et al., doi: 10.1016/j.icarus.2021.114805.
“Overall, we think this water more likely exists in the form of ice,” he stated.
“Water ice usually evaporates in this region of Mars due to the temperature and pressure conditions near the equator.”
“The same applies to chemically bound water: the right combination of temperature, pressure and hydration must be there to keep minerals from losing water.”
“This suggests that some special, as-yet-unclear mix of conditions must be present in Valles Marineris to preserve the water — or that it is somehow being replenished.”
“This finding is an amazing first step, but we need more observations to know for sure what form of water we’re dealing with,” stated Dr. Håkan Svedhem, a researcher at ESA’s ESTEC.
“Regardless of the outcome, the finding demonstrates the unrivalled abilities of TGO’s instruments in enabling us to ‘see’ below Mars’ surface — and reveals a large, not-too-deep, easily exploitable reservoir of water in this region of Mars.”
The findings seem within the journal Icarus.
_____
I. Mitrofanov et al. 2022. The proof for unusually excessive hydrogen abundances within the central a part of Valles Marineris on Mars. Icarus 374: 114805; doi: 10.1016/j.icarus.2021.114805