Carbon Dioxide Cold Traps on the Moon

Abstract

Water ice is expected to be trapped in permanently cold regions near the lunar poles. Other ices (“super-volatiles”) are trapped at lower temperatures, close to the lowest temperatures measured within the lunar permanently shadowed regions (PSRs). Here, the thermal stability of solid carbon dioxide in the south polar region is determined by analysis of 11 years of temperature measurements by Diviner, a radiometer onboard the Lunar Reconnaissance Orbiter. Sublimation rates averaged over a draconic year are far lower than peak sublimation rates. Small spatially contiguous pockets of CO2 ice stability are found in the craters Amundsen, Haworth, de Gerlache, and others, over a cumulative area of roughly 200 km2. The LCROSS probe impacted one of those pockets and released CO2, serving as validation of the thermal stability calculations. Future surface missions can utilize this highly localized resource for the production of fuel, steel, and biological materials.