Chandrayaan-2 Finds Ice Under the Moon’s Surface — Six Years On

General Studies Paper 3 — Science and Technology, Space
Source: Physical Research Laboratory (PRL), Ahmedabad / ISRO, 2026

1. What happened

Scientists at the Physical Research Laboratory (PRL), Ahmedabad have found evidence of subsurface water-ice near the Moon’s South Pole using data from the Chandrayaan-2 orbiter — nearly six years after its 2019 launch. The finding was made using its Dual Frequency Synthetic Aperture Radar (DFSAR) payload.

Despite losing the Vikram lander during its descent on September 7, 2019, the Chandrayaan-2 orbiter has remained fully functional and continues to produce high-value scientific data.

2. India’s lunar water discovery — a progression

From Chandrayaan-1 to Chandrayaan-2 — building on each discovery

Chandrayaan-1 (2008) — Surface Hydration Discovered

Moon Mineralogy Mapper (M3) payload detected widespread water molecules on the lunar surface. This fundamentally changed what scientists believed about the Moon — previously thought to be completely dry.

Discovery: Surface water molecules (hydration)

Chandrayaan-2 goes deeper ↓

Chandrayaan-2 (2026 Finding) — Sub-surface Ice Detected

DFSAR radar penetrates lunar dust (regolith) and finds ice buried under the surface inside permanently shadowed craters at the South Pole — where temperatures stay around -248°C (25 Kelvin). Strongest evidence found in a crater within Faustini crater.

Discovery: Sub-surface ice deposits at South Pole

Why DFSAR works where cameras fail: An optical camera can only photograph the surface — like taking a photo of a closed book cover. DFSAR sends microwave signals that pass through dust and bounce back from what is buried inside — like an X-ray scanning what is inside the book.

3. Why this discovery matters — the strategic value of lunar ice

Permanently Shadowed Regions (PSRs)

The Moon’s axial tilt is only 1.5° — so sunlight never reaches the bottoms of deep craters near the poles. Temperatures stay at -248°C, perfectly preserving ice for billions of years.

In-Situ Resource Utilisation (ISRU)

Launching water from Earth into space costs millions of dollars per litre. Moon-mined ice can be used for drinking water, radiation shielding, and split into hydrogen and oxygen for rocket fuel — directly on the Moon.

Race for the South Pole

The lunar South Pole is the most sought-after destination for future missions — including NASA’s Artemis programme and India’s Chandrayaan-4. India’s early mapping gives it scientific and diplomatic leverage in future international lunar base negotiations.

4. Value Box — Key Terms and Institutions

Physical Research Laboratory (PRL), Ahmedabad

India’s premier space and atmospheric sciences research institute. Under the Department of Space. Founded in 1947 by Vikram Sarabhai — considered the father of India’s space programme.

Dual Frequency Synthetic Aperture Radar (DFSAR)

A microwave radar on Chandrayaan-2’s orbiter. Operates in L-band and S-band frequencies. Can penetrate lunar dust to detect subsurface materials — unlike optical cameras which only see the surface.

In-Situ Resource Utilisation (ISRU)

Using materials found at a space destination — rather than carrying everything from Earth. Lunar ice for water and rocket fuel is the most discussed ISRU application. Critical for sustainable long-term human presence on the Moon.

Prelims Practice Question

Consider the following statements regarding Chandrayaan missions and the recent lunar ice discovery:

1. Chandrayaan-1’s Moon Mineralogy Mapper detected water molecules on the lunar surface, while Chandrayaan-2’s DFSAR has provided evidence of sub-surface ice deposits near the South Pole.
2. The Chandrayaan-2 Vikram lander successfully soft-landed on the Moon’s surface on September 7, 2019, making India the fourth country to achieve a lunar soft landing.
3. The Physical Research Laboratory, Ahmedabad — which published the recent ice findings — functions under India’s Department of Space and was founded by Vikram Sarabhai.

Which of the statements given above is/are correct?

• (a) 1 and 3 only
• (b) 2 and 3 only
• (c) 1 and 2 only
• (d) 1, 2 and 3

Answer: (a) 1 and 3 only