ESA’s Mars orbiter TGO found “significant amounts” of water on the floor of the largest canyon on Mars and surprised the research team responsible. So far, if water – in the form of ice – has been found on Mars, it has primarily been at the poles. At lower latitudes, only small amounts have so far been detected – at least on the surface.
The water-rich area in Valles Marineris that has now been discovered is roughly the size of the Netherlands (around 42,000 square kilometers), and up to 40 percent of the material directly under the surface there could be water. The measurements do not reveal the physical state in which the water is present. Data collected from other analyzes suggest that it is frozen. It is located in the first meter of the floor.
The occurrence found directly on the surface
(Image: I. Mitrofanov et al. (2021))
Tell-tale neutrons
The deposit was found with a neutron telescope called FREND (Fine Resolution Epithermal Neutron Detector) on board the Trace Gas Orbiter, the researchers explain. The instrument searches for neutrons that originate from the surface and indicate hydrogen – their amount varies depending on the humidity. That he struck gold in the middle of the largest canyon in the solar system was unexpected, writes the team around Igor Mitrofanov from the Russian Academy of Sciences. In this region of the Red Planet, water usually evaporates due to the temperature and pressure conditions. Minerals here usually only contained a few percent water. The find therefore suggests that either the circumstances are particularly favorable at this location or that the water supply is somehow always being replenished.
While water has already been found at greater depths in these latitudes, the reservoirs are not as interesting as the one at the bottom of the Valles Marineris just because of their inaccessibility. So it is ideal for further missions. The canyon has been fascinating on earth for a long time because it is reminiscent of the famous Grand Canyon in the USA, but at the same time it is about ten times as large and five times deeper. The Trace Gas Orbiter, which has now found so much water there, was launched in 2016. It is part of the ExoMars program of ESA and the Russian space agency Roskosmos. This also includes a rover that will finally start in the coming year. The researchers are now presenting the water find in the specialist magazine Icarus.
(mho)