Using data from a NASA radar that flew aboard India's Chandrayaan-1 spacecraft, scientists have detected ice deposits near the moon's north pole. NASA's Mini-SAR instrument, a lightweight, synthetic aperture radar, found more than 40 small craters with water ice. The craters range in size from 2 to15 km in diameter. Although the total amount of ice depends on its thickness in each crater, it's estimated there could be at least (600 million metric tonnes) of water ice.
The discovery indicates that water creation, migration, deposition and retention are occurring on the moon.
Mini-SAR map of the Circular Polarization Ratio (CPR) of the north pole of the Moon. Fresh, “normal” craters (red circles) show high values of CPR inside and outside their rims. This is consistent with the distribution of rocks and ejected blocks around fresh impact features, indicating that the high CPR here is surface scattering. The “anomalous” craters (green circles) have high CPR within, but not outside their rims. Their interiors are also in permanent sun shadow. These relations are consistent with the high CPR in this case being caused by water ice, which is only stable in the polar dark cold traps.
During the past year, the Mini-SAR mapped the moon's permanently-shadowed polar craters that aren't visible from the earth. The radar uses the polarization properties of reflected radio waves to characterize surface properties. Results from the mapping showed deposits having radar characteristics similar to ice.
WATER ON THE MOON DECADE-LONG SPECULATION ENDS
During the past year, the Mini-SAR mapped the moon's permanently-shadowed polar craters that aren't visible from the earth. The radar uses the polarization properties of reflected radio waves to characterize surface properties. Results from the mapping showed deposits having radar characteristics similar to ice.