The presence of "significant amounts" of water has been discovered beneath the soil of Mars in a system of canyons known as Valles Marineris, or the Mariner Valley, the European Space Agency (ESA) announced.
According to a statement posted on the space agency’s official website, the discovery was made via the ESA-Roscosmos’ Trace Gas Orbiter’s (TGO) Fine-Resolution Epithermal Neutron Detector (FREND) instrument that can detect hydrogen “in the uppermost metre of the planet’s soil.”
"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 Igor Mitrofanov of the Space Research Institute of the Russian Academy of Sciences in Moscow, Russia, lead author of the new study and FREND’s principal investigator.
As Mitrofanov explained, FREND "revealed an area with an unusually large amount of hydrogen in the colossal Valles Marineris canyon system". The scientist further suggested that, "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".
"We found a central part of Valles Marineris to be packed full of water – far more water than we expected," added Mitrofanov’s co-author Alexey Malakhov, also of the Space Research Institute of the Russian Academy of Sciences. "This is very much like Earth’s permafrost regions, where water ice permanently persists under dry soil because of the constant low temperatures."
While the water detected by TGO may potentially be "chemically bound to other minerals in the soil", other observations suggest that "minerals seen in this part of Mars typically contain only a few percent water, much less than is evidenced by these new observations".
"Overall, we think this water more likely exists in the form of ice," Malakhov remarked.
Another study co-author, Hakan Svedhem from ESA’s ESTEC in the Netherlands, described the new discovery as "an amazing first step", but pointed at the necessity for "more observations to know for sure what form of water we’re dealing with".