In a major breakthrough for space exploration, scientists from the Physical Research Laboratory (PRL) have uncovered compelling evidence of subsurface water ice tucked away in the Moon’s darkest, coldest corners. Using high-resolution data from the Indian Space Research Organisation’s (ISRO) Chandrayaan-2 orbiter, researchers have identified radar signatures consistent with buried ice deposits within “doubly shadowed craters” near the lunar south pole—regions that have remained shielded from sunlight and thermal radiation for billions of years.
The discovery, published in the journal npj Space Exploration, highlights a significant milestone for India’s lunar research program. By utilising the orbiter’s Dual Frequency Synthetic Aperture Radar (DFSAR), scientists were able to probe beneath the lunar surface, moving beyond previous surface-level observations to confirm the presence of volatile reserves that could prove essential for future human habitation.
Unmasking the Moon’s Hidden Ice
The study specifically targeted “doubly shadowed craters”—small, secluded depressions located within permanently shadowed regions (PSRs) where temperatures can plummet to a staggering 25 Kelvin (approximately -248°C). These ultra-cold environments are considered ideal “cold traps” for preserving water ice over geological timescales.
To distinguish between mere rocky debris and genuine ice deposits, the research team developed a sophisticated radar-based criterion. By analysing the Circular Polarisation Ratio (CPR) and the Degree of Polarisation (DOP), they successfully identified volumetric scattering—a radar effect that strongly indicates the presence of subsurface ice. Among the four sites identified, a 1.1-kilometre-wide crater within the larger Faustini crater emerged as the most promising site, exhibiting distinct “lobate-rim” features that suggest an ancient impact likely penetrated an ice-rich subsurface layer.
A New Frontier for Lunar Exploration
The implications of these findings are profound for the next generation of space missions. Water-ice is widely regarded as the “gold” of lunar resources; if accessible, it can be processed into drinking water, breathable oxygen, and even hydrogen-based rocket fuel. Identifying these specific ice-bearing regions is a critical step for in-situ resource utilisation (ISRU), a strategy central to the ambitions of India’s planned crewed lunar missions and international efforts to establish long-term lunar bases.
ISRO officials have hailed the discovery as a testament to the enduring scientific value of the Chandrayaan-2 orbiter, which has continued to deliver high-quality data years after its arrival in lunar orbit. As India gears up for the LUPEX (Lunar Polar Exploration) mission—a collaborative project with Japan’s JAXA—these latest findings provide a precise roadmap for where future landers and rovers might touch down to extract the water necessary to sustain a human presence on the Moon.
