New study points to reachable water ice in moon’s polar craters

Bengaluru: Findings from a recent study anchored by Indian and international space scientists have revealed an “enhanced possibility” of water ice occurrence in the moon’s polar craters, the Indian Space Research Organisation (Isro) said.

The collaborative study undertaken by scientists of Isro’s Space Applications Centre (SAC) and researchers at IIT Kanpur, University of Southern California, Jet Propulsion Laboratory, and IIT (Indian School of Mines) Dhanbad indicated that the amount of subsurface ice in the first couple of metres is about five to eight times larger than at the surface in both poles.

The new findings suggested that the extent of water ice in the northern polar region is twice that in the southern polar region. These findings are expected to inform strategies for selecting future in-situ water ice sampling sites at the lunar poles. They find greater relevance against the backdrop of the increasing number of lunar exploration programmes that include the Isro-JAXA mission LuPEx, NASA’s robotic rover mission VIPER, and future Chang’E lunar probes by China, the researchers said.

The researchers carried out the study using seven instruments comprising radar, optical, neutron spectrometer, ultra-violet spectrometer, and thermal radiometer onboard NASA’s Lunar Reconnaissance Orbiter (LRO) to study the origin and distribution of water ice on the moon.

They did not rule out the possibility of deep-seated water ice deposits in the lunar poles that remain beyond the detection capabilities of existing LRO instruments.

The study, titled ‘On the reachability and genesis of water ice on the moon’, was published in ISPRS Journal of Photogrammetry and Remote Sensing. It confirmed the hypothesis that the primary source of subsurface water ice in the lunar poles is outgassing (release of gases from the lunar interior) during volcanism in the Imbrian period, between 3.8 and 3.2 billion years ago.

Isro said the findings also supported a previous SAC study that indicated the presence of water ice in some of the polar craters, utilising polarimetric radar data from the Chandrayaan-2 dual-frequency Synthetic Aperture Radar.