What Happened
- A new international study published in the journal npj Space Exploration (2026) used data from ISRO's Chandrayaan-2 mission to reveal that water ice deposits in the Moon's permanently shadowed regions (PSRs) are more stable than previously understood.
- The study found that approximately 74% of PSRs are unaffected by impact gardening — the process by which meteorite impacts vertically mix surface materials, potentially disrupting ice layers.
- The remaining 26% of PSRs that have been impacted may actually preserve ice at depth through mixing with ejecta, rather than necessarily destroying it.
- These findings significantly improve the scientific understanding of lunar water resources and have direct implications for planning future crewed lunar missions and the establishment of permanent lunar habitats.
- Chandrayaan-2's Dual Frequency Synthetic Aperture Radar (DFSAR) instrument — capable of penetrating the lunar subsurface — contributed critical data to this assessment.
Static Topic Bridges
Chandrayaan-2 Mission: Objectives and Instruments
Chandrayaan-2 is India's second lunar exploration mission, launched by ISRO on July 22, 2019. The mission consisted of an Orbiter, a Lander (Vikram), and a Rover (Pragyan). While the lander crashed during descent on September 7, 2019, the Orbiter continues to function successfully and has been generating high-quality scientific data. The mission objective included mapping the lunar surface, studying the lunar exosphere, and searching for water-ice deposits in PSRs.
- Chandrayaan-2 Orbiter carries 8 scientific payloads including IIRS (Imaging Infrared Spectrometer), DFSAR (Dual Frequency Synthetic Aperture Radar), CLASS (Chandrayaan-2 Large Area Soft X-ray Spectrometer), and others.
- DFSAR operates in both L-band and S-band using full polarimetry — offering greater penetration depth and resolution than any prior lunar radar instrument.
- IIRS data provided the first unambiguous detection of water/hydroxyl on the lunar surface during daylight hours.
- The Orbiter has a mission lifespan extended to approximately 7.5 years from launch, due to precise orbit insertion saving fuel.
Connection to this news: Chandrayaan-2's DFSAR instrument provided the subsurface radar data that underpins the 2026 international study's findings on PSR stability, demonstrating the continued scientific value of the mission's orbital component.
Permanently Shadowed Regions (PSRs) and Lunar Water Ice
Permanently Shadowed Regions (PSRs) are areas near the lunar poles — typically the floors of deep polar craters — that never receive direct sunlight due to the Moon's low axial tilt (approximately 1.54° relative to the ecliptic). Temperatures in PSRs can drop to below -230°C, making them among the coldest known places in the Solar System. These extreme cold conditions allow volatiles, including water ice, to persist for billions of years.
- Current estimates suggest the Moon's poles host more than 600 billion kg of water ice — equivalent to at least 240,000 Olympic-sized swimming pools.
- Water ice was first confirmed on the Moon's surface at PSRs in 2018 via data from the Moon Mineralogy Mapper (M3) aboard Chandrayaan-1.
- PSRs are concentrated near the lunar south pole — the primary target of India's Chandrayaan-3 mission (successful soft landing, August 2023) and NASA's Artemis programme.
- The stability of PSR water ice is a critical factor in the viability of In-Situ Resource Utilisation (ISRU) — using lunar water for drinking water, oxygen production (electrolysis), and hydrogen rocket fuel for crewed missions.
Connection to this news: The new study's finding that 74% of PSRs are unaffected by impact gardening significantly increases confidence that surface-accessible water ice exists in sufficient quantities and stability to support future lunar operations.
India's Lunar Programme: Chandrayaan Series
India's lunar exploration programme has progressively expanded its scientific and technological ambitions. Chandrayaan-1 (2008) discovered water molecules on the lunar surface. Chandrayaan-2 (2019) demonstrated advanced orbital mapping capabilities. Chandrayaan-3 (2023) achieved India's first successful soft landing near the lunar south pole, making India the fourth country to soft-land on the Moon and the first to land near the south pole.
- Chandrayaan-1 launched: October 22, 2008; Moon Impact Probe (MIP) released: November 14, 2008 (Jawaharlal Nehru's birth anniversary — now celebrated as National Space Day).
- Chandrayaan-3 Lander (Vikram) landed: August 23, 2023; this date is now commemorated as National Space Day in India.
- Chandrayaan-3's Pragyan Rover confirmed sulphur and other elements near the south pole.
- Chandrayaan-4 is planned as a lunar sample-return mission.
Connection to this news: The continued scientific output from Chandrayaan-2's Orbiter — now contributing to international studies on lunar water ice stability — validates India's strategy of maintaining long-duration orbital missions with multidisciplinary payloads.
Key Facts & Data
- Chandrayaan-2 launched: July 22, 2019; Orbiter continues operational.
- 74% of permanently shadowed regions (PSRs) found to be unaffected by impact gardening (npj Space Exploration, 2026).
- Estimated lunar polar water ice: over 600 billion kg.
- DFSAR operates in L-band and S-band using full polarimetry — highest-resolution lunar subsurface radar to date.
- Chandrayaan-1 first detected water molecules on the Moon: 2008.
- Chandrayaan-3 first soft-landed near lunar south pole: August 23, 2023.
- Moon's axial tilt: approximately 1.54° — reason PSRs never receive sunlight.
- PSR temperatures: below -230°C.
- Chandrayaan-4: planned as lunar sample-return mission.