Local water-rich areas on Mars found by the FREND neutron telescope onboard ExoMars TGO

Fine Resolution Epithermal Neutron Detector (FREND) is an instrument onboard ExoMars' Trace Gas Orbiter. Its measurements of epithermal neutron flux on orbit provide data on hydrogen (and thus, water) content in the 1-m thick near-surface regolith layer. Similar experiments have been performed before, neutron sounding is a well-established technique for estimating water content in the celesital body's soil. FREND's chatacteristic feature is its collimator - a massive body surrounding detectors and narrowing their field of view substantially, thus providing for very high spatial resolution, around 60 to 200 km, depending on measurement conditions. Such spatial resolution allows identifying local water-rich features with relief and other geomorphological features, assess water content in small ellipses of future landing sites.

In this study we present latest findings based on FREND data, containing a number of surprisingly "wet" local features in the equatorial band. Water or water ice is not stable at the surface of Mars, in the equatorial regions especially, that is why locating areas with enhanced subsurface hydrogen or water is of much interest both to scientists and for the purpose of planning future exploration missions.