Analysis of data obtained by the Miniature Synthetic Aperture Radar (Mini-SAR) onboard Chandrayaan-1 spacecraft has provided evidence for the presence of ice deposits near the moon's North Pole. The Mini-SAR instrument found more than 40 small craters (2-15 km in diameter) with sub-surface water ice located at their base. The interior of these craters is in permanent sun shadow.  

Prof. Paul Spudis, Principal Investigator of the Mini-SAR experiment said, “The new discoveries by Chandrayaan-1 and other lunar missions show that the moon is an even more interesting and attractive scientific exploration and operational destination than people had previously thought.”  

The Mini-SAR mapped the moon’s permanently shadowed polar craters that are not visible from Earth. The radar uses the polarisation properties of reflected radio waves to characterise surface properties. Results from the mapping showed deposits having radar characteristics similar to ice. The emerging picture from the multiple measurements and resulting data of the instruments, Moon Mineralogy Mapper and Mini-SAR on Chandrayaan-1 and NASA's Lunar Crater Observation and Sensing Satellite (LCROSS), indicates that water creation, migration, deposition and retention are occurring on the moon. 

The Mini-SAR's findings have just been published in the journal, “Geophysical Research Letters” authored by scientists from 13 agencies from USA and India, including Prof. J.N. Goswami, Principal Scientist, Chandrayaan-1 from Physical Research Laboratory, Ahmedabad and Dr. M. Chakrabarty of Space Applications Centre, Ahmedabad. The new findings add to the growing scientific understanding of the multiple forms of water on the moon.  

Mini-SAR and Moon Mineralogy Mapper are two of the 11 instruments on Chandrayaan-1, which was launched on October 22, 2008, and began orbiting the moon on November 8, 2008. The Applied Physics Laboratory, USA performed the final integration and testing on Mini-SAR. It was developed and built by the Naval Air Warfare Center and several other commercial and government agencies in USA.  

For more information about NASA's Mini-SAR, also known as Mini-RF, please visit: http://www.nasa.gov/mini-rf