There could be as much as 600 million metric tonnes of water ice in the dark craters near the moon’s north pole, say scientists after analysing data brought back by the Chandrayaan-1 moon mission.
“The new findings show that the moon is an even more interesting destination than people previously thought,” said Paul Spudis, principal investigator for the project and a scientist at the Lunar and Planetary Institute in Texas, US.
A tiny radar sensor, Mini-SAR, discovered the caches of frozen water.
Mini-SAR was created by the United States-based National Aeronautics and Space Administration (NASA). The sensor weighs less than 10 kg, six times lighter than an unabridged Oxford English Dictionary. Mini-SAR arrived at the moon aboard Chandrayaan-1.
The sensor circled the lunar poles — the darkest, coldest and least explored parts of the moon’s surface — for three months in early 2009. Mini-SAR fired a series of radio pulses at the moon. Near the North Pole, the feedback from the surface — the radio waves that bounced back — suggested the presence of water ice.
“The finding will give future missions a new target to explore and exploit,” said Jason Crusan, programme executive for the Mini-RF Program for NASA's Space Operations Mission Directorate in Washington.
The new findings are part of a flood of recent discoveries of lunar water. Together, the findings have revolutionized the way scientists look at the moon.
In November, NASA’s Lunar Crater Observation and Sensing Satellite mission (LCROSS) discovered water vapour near the Cabeus crater at the moon’s south pole. The Cabeus crater lies under a deep and permanent layer of shadow.
“The moon is alive!” crowed principal investigator Anthony Colaprete, chief scientist for LCROSS, upon announcing the discovery. Colaprete held up 95 litres of water, the amount discovered by LCROSS.
Scientists have long suspected that if there is water on the moon, it is hidden at the poles. Astronauts who have visited the moon have brought back kilograms of samples and elaborate maps of the lunar equator, but the poles remained shrouded in mystery.
Over the past few months, scientists have been chipping away at that mystery, looking at data brought back by the 11 instruments aboard Chandrayaan-1.
In September, scientists from India and the US announced the discovery of water molecules on the moon’s surface.
It will take scientists two years to sort through all the Chandrayaan-1 data. But the results have already gotten researchers fired up.
The Mini-SAR findings, authored by Indian and American scientists from more than 13 agencies, appeared Tuesday in the journal Geophysical Research Letters.