Ranit Kr. Singh , New Delhi — Scientists from the Physical Research Laboratory (PRL) in Ahmedabad have discovered strong evidence of hidden subsurface water-ice within "doubly shadowed craters" near the lunar south pole. Published in a *Nature* portfolio journal, the breakthrough utilized advanced polarimetric data from the Dual Frequency Synthetic Aperture Radar (DFSAR) instrument active aboard the Indian Space Research Organisation's (ISRO) Chandrayaan-2 orbiter. This finding marks a major step forward in identifying localized resources that could sustain future international crewed missions and long-term lunar bases.

The exploration focused on nine specific areas shielded completely from direct sunlight and reflected thermal radiation, where temperatures plummet to a freezing 25 Kelvin (around minus 248 degrees Celsius). By introducing a refined screening method that combines a Circular Polarization Ratio greater than 1 with a Degree of Polarization under 0.13, researchers managed to distinguish actual ice signatures from rocky, rough terrain. This advanced microwave imaging successfully mapped subsurface volatile deposits buried beneath the floors of four targeted, ultra-cold craters.

Among the examined formations, a 1.1-kilometer-wide crater nested inside the massive Faustini crater stands out as the most definitive reservoir. Beyond revealing significant radar anomalies, the crater exhibits a unique lobate-rim morphology, indicating a distinct flow-like design. Geologists believe the meteor impact that formed this specific crater originally penetrated an existing underground ice layer, causing the mud-like structural flow. ISRO noted that these localized deposits could eventually serve as critical in-situ resources, providing future astronauts with drinking water, breathable oxygen, and processed rocket propellant.