The permanently dark regions around the south pole have the radar reflectance properties suggestive of ice, rather than the ground up rock powder characteristic of the rest of the Moon's surface. Additional data taken on orbits where the reflected radio spots were not over these south polar regions and at the north pole do not show this ice signature. This negative result is expected for these regions because they are all illuminated by the Sun during the course of the lunar day. The total area of permanent darkness near the south pole exceeds 15,500 km2, about twice the areal extent of the island of Puerto Rico. The discovery of ice on the Moon has enormous implications for a permanent human return to the Moon.
Water ice is made up of hydrogen and oxygen, two elements vital to human life and space operations.
Lunar ice could be mined and disassociated into hydrogen and oxygen by electric power provided by solar panels or a nuclear generator. Additionally, the water from lunar polar ice and oxygen generated from the ice could support a permanent facility or outpost on the Moon. The discovery of this material, rare on the Moon but so vital to human life and operations in space, will make human expansion into the Solar System easier and reaffirms the immense value of our own Moon as the stepping stone into the universe.