Nearly six years after its launch, India’s Chandrayaan-2 spacecraft continues to yield breakthrough lunar data.
Using advanced polarimetric radar analysis, scientists from the Physical Research Laboratory (PRL) have found strong evidence of subsurface water ice beneath four doubly shadowed craters in the Moon’s permanently shadowed regions (PSRs).
Due to continuous shielding from sunlight and thermal radiation, these regions maintain temperatures as low as -25K, serving as ideal environments for preserving water ice over long geological timescales.
The breakthrough was achieved using data from the spacecraft’s Dual Frequency Synthetic Aperture Radar (DFSAR) payload.
“The study proposes a refined radar-based criterion for identifying subsurface ice, where Circular Polarization Ratio (CPR) values greater than 1, together with Degree of Polarization (DOP) values lower than 0.13, indicate volumetric scattering potentially associated with subsurface ice,” the Indian Space Research Organisation (ISRO) stated.
Nearly six years after its launch, India’s Chandrayaan-2 spacecraft continues to yield breakthrough lunar data. Using advanced polarimetric radar analysis, scientists from the Physical Research Laboratory (PRL) have found strong evidence of subsurface water ice beneath four doubly shadowed craters in the Moon’s permanently shadowed regions (PSRs). Due to continuous shielding from sunlight and thermal radiation, these regions maintain temperatures as low as -25K, serving as ideal environments for preserving water ice over long geological timescales.
The breakthrough was achieved using data from the spacecraft’s Dual Frequency Synthetic Aperture Radar (DFSAR) payload. To differentiate genuine ice from rough, rocky terrain, researchers established precise radar criteria. “The study proposes a refined radar-based criterion for identifying subsurface ice, where Circular Polarization Ratio (CPR) values greater than 1, together with Degree of Polarization (DOP) values lower than 0.13, indicate volumetric scattering potentially associated with subsurface ice,” the Indian Space Research Organisation (ISRO) stated.
Particularly strong evidence was observed in a 1.1 km wide crater inside the Faustini crater. According to ISRO, its radar signature is supported by distinctive lobate-rim features, suggesting that the initial “impact may have penetrated subsurface ice, producing the observed lobate-rim crater.” These discoveries are crucial for mapping polar volatiles to guide future landing site selection and in-situ resource utilization (ISRU).
