Water IceProspecting — mapped / surveyed

Polar Water Ice Caps

North and South Poles; north cap is water ice year-round, south cap CO2 ice over water ice

Orbital view of Mars' bright north polar ice cap with its spiral troughs — Image: NASA/JPL-Caltech/MSSS (Mars Global Surveyor)

Estimated Quantity

~3.7 million km³ equivalent water

Enough water to cover Mars to a depth of ~35 meters if melted

As of 2021-01-01

Location & ISRU Feasibility

Where

Planum Boreum (~88°N) and Planum Australe (~87°S)

Extraction feasibility

Low feasibility

Largest confirmed water reservoirs, but the poles sit far from viable crewed landing zones (which must stay near the equator-to-mid-latitude band for thermal survival and descent margin), so polar ice is impractical as a first-mission feedstock.

Extraction technology

Conceptual surface/near-surface mining (heated drilling or thermal excavation) of high-purity layered ice mapped by MRO/SHARAD; not yet demonstrated on Mars.

Overview

Mars's polar caps contain substantial water ice. The north polar cap is nearly pure water ice (600 m deep, 1,000 km wide) covered in seasonal CO2 frost. SHARAD radar on MRO has mapped the layers in detail. MOLA topography confirms the south cap is offset from geographic south pole and buried under CO2. These are the largest confirmed water repositories on Mars.

ISRU Application

Electrolysis to produce rocket propellant (H₂+O₂), life support water and oxygen for crewed missions, radiation shielding via water walls

Reality Check

Polar ice is far from equatorial landing sites — nearest useful water ice deposits are mid-latitude subsurface glaciers

Sources

[1] NASA Science (SWIM) — retrieved 2026-06-13
[2] NASA MRO/SHARAD — retrieved 2026-06-01

Confidence: high · Last verified 2026-06-01

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