'Significant' Amounts of Water Discovered Under Mars Grand Canyon Feature in Historic Find

The European Space Agency's and Russian space agency Roscosmos' ExoMars Trace Gas Orbiter (TGO) discovered "significant amounts" of water in Mars, the ESA said in a Wednesday announcement. This water was hidden underneath the surface of the Red Planet's Valles Marineris canyon system, an area ten times longer and five times deeper than Earth's Grand Canyon.

While water has been found on Mars before, most of it is contained in the planet's cold polar regions as ice, the ESA reports. Most of the water remains in this area because temperatures there are not cold enough for exposed water ice to be stable at the planet's equator.

For some time, the ESA has hunted for water near Mars' surface and has only previously found small amounts, mostly in soil and locked in minerals. This recent finding signified that the planet could contain deeper water stores covered by dust.

"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," Igor Mitrofanov of the Space Research Institute of the Russian Academy of Sciences, who authored the new study, said in a statement.

"(The Fine Resolution Epithermal Neutron Detector neutron telescope) 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 [percent] of the near-surface material in this region appears to be water," the statement continued.

The ESA report states that the area comprises a space roughly the size of the Netherlands and comes in contact with the valleys of Candor Chaos, a part of the canyon system that the agency considers "promising in our hunt for water on Mars."

According to the ESA, this finding marks Valles Marineris as an "even more promising target" for future exploration. While water has been found a few "kilometers below ground" before deep underground at the planet's mid-latitudes and under its south pole, the ESA said these areas are less accessible to exploration than the water just found given their deep distance.

"Knowing more about how and where water exists on present-day Mars is essential to understand what happened to Mars' once-abundant water, and helps our search for habitable environments, possible signs of past life, and organic materials from Mars' earliest days," Colin Wilson, ESA's ExoMars Trace Gas Orbiter project scientist, said in a statement.