Why the Moon's South Pole Has Become the Most Contested Patch of Lunar Real Estate

The floors of certain craters near the Moon's south pole have not seen sunlight in roughly two billion years. Because the Moon's axial tilt is only 1.5 degrees, almost perfectly upright compared to Earth's 23.5, the Sun never rises high enough to reach into those crater basins. Temperatures there sit around minus 250 degrees Celsius, colder than the surface of Pluto. At that temperature, water ice deposited by ancient comets and asteroids does not sublimate. It just stays, buried under a thin layer of regolith, preserved in what scientists call permanently shadowed regions, or PSRs.

NASA's LCROSS mission confirmed this in 2009 by deliberately crashing a rocket stage into the Cabeus crater near the south pole and analysing the debris plume. Spectrometers detected water vapour, ice crystals, and several other volatiles. The quantity wasn't trivial: estimates from subsequent orbital data suggest the lunar south pole region may hold hundreds of millions of tonnes of water ice. India's own Chandrayaan-1, launched in 2008, had already provided key data through its Moon Mineralogy Mapper instrument, which detected hydroxyl and water molecules across the lunar surface, a finding that shifted the entire scientific consensus about a dry Moon.

The reason every agency is racing toward the same patch of ground comes down to chemistry. Water, H2O, can be split by electrolysis into hydrogen and oxygen. Liquid hydrogen and liquid oxygen are exactly what rocket engines burn. A depot of water ice at the lunar south pole is, in practical terms, a refuelling station sitting 384,000 kilometres from Earth. Launching fuel from Earth's gravity well is extraordinarily expensive. Producing it on the Moon from local ice changes the economics of deep-space exploration entirely. A crewed mission to Mars that refuels at a lunar base needs to carry far less propellant from Earth. The ice is not a side benefit. It is the architecture that makes sustained space exploration financially possible.

Drinking water and radiation shielding are secondary gains. Water is also an effective barrier against cosmic radiation, so ice-derived water packed around habitat walls would protect crews during long surface stays. The south pole's elevated terrain, ridges and crater rims that catch near-continuous sunlight, also makes solar power generation viable right next to the PSRs. You get permanent shadow for ice storage and near-permanent sun for electricity within a few kilometres of each other. That combination does not exist anywhere else on the Moon.

When Chandrayaan-3's Vikram lander touched down on August 23, 2023, it made India the fourth country to achieve a soft lunar landing and the first to land near the south pole, at approximately 69 degrees south latitude. The Pragyan rover that rolled out from it carried instruments including the Laser-Induced Breakdown Spectroscope and the Alpha Particle X-ray Spectrometer. ISRO confirmed the presence of sulphur, iron, oxygen, aluminium, calcium, chromium, titanium, manganese, and silicon in the regolith. The search for water ice directly in the soil was constrained by the landing site's illuminated terrain, Pragyan couldn't enter the permanently shadowed craters, but the mission established India's technical capability to operate at the pole and characterised the surface chemistry of the region.

ISRO's future plans include Chandrayaan-4, which is being designed as a sample-return mission, and a collaborative lunar polar exploration mission with JAXA, the Japanese space agency, called LUPEX. LUPEX is specifically designed to drive a rover into shadowed regions and drill into the regolith to measure subsurface water ice content directly. The data it returns will determine whether the ice is accessible enough to mine.

NASA's Artemis programme has identified thirteen candidate landing regions near the south pole, all chosen partly for proximity to PSRs. The Lunar Trailblazer orbiter, scheduled to map water distribution from orbit, and the VIPER rover, designed to prospect for ice on the surface, are both aimed at the same region. China's Chang'e programme has announced south pole ambitions, with Chang'e-7 targeting the Shackleton crater rim. Russia's Luna-25 attempted a south pole landing in 2023 and crashed. The competition is real, and it is accelerating.

The legal situation is genuinely unresolved. The 1967 Outer Space Treaty prohibits national sovereignty over the Moon but does not clearly address resource extraction. The United States-led Artemis Accords, which India signed in 2023, establish a framework for safety zones and resource use, but they are bilateral agreements, not binding international law. China and Russia have not signed them. The question of who can mine lunar ice, and under what rules, remains open, and the answer will matter enormously once the technology to do so actually exists.

For most of the Apollo era, the Moon was a destination. Six missions landed, collected samples, and came home. The south pole ice converts the Moon into infrastructure. A permanent base near the pole, drawing on local water for fuel production and radiation shielding, becomes a waystation rather than an endpoint, a place from which spacecraft depart for deeper destinations rather than a place humans visit and leave.

ISRO's incremental approach to this, from Chandrayaan-1's water detection to Chandrayaan-3's polar landing to the planned LUPEX ice-prospecting mission, reflects a considered path toward that infrastructure role. India did not get to the south pole first by accident. The scientific case for the pole has been clear since 2009. The Chandrayaan programme was built around it.

The south pole's ice, the solar power on its ridges, and the permanently shadowed craters holding both together form a system that no other location on the Moon replicates. Every mission now converging on those coordinates is converging on the same underlying logic: the Moon's value as a platform for the rest of space depends almost entirely on what is frozen in those lightless basins. The race to the south pole is not about the Moon. It is about everywhere beyond it.