Why in News?

• The NASA scientists, using data from the Chandrayaan-I spacecraft, on August 21, 2018 confirmed that there are frozen water deposits in the darkest and coolest parts of Moon’s Polar Regions. The findings were published in the journal Proceedings of the National Academy of Sciences (PNAS).
• The Chandrayaan-I spacecraft was launched in 2008 by the Indian Space Research Organisation (ISRO).

NASA’s Moon Mineralogy Mapper (M3) is testimony:

• M3, aboard the Chandrayaan-1 spacecraft, launched in 2008 by the Indian Space Research Organisation (ISRO), was uniquely equipped to confirm the presence of solid ice on the Moon.
• Scientists used data from NASA’s Moon Mineralogy Mapper (M3) instrument to identify three specific signatures that definitively prove there is water ice at the surface of the Moon.
• It collected data that not only picked up the reflective properties we would expect from ice, but was also able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapour and solid ice.

National Academy of Sciences (PNAS)- Study:

• Scientists have directly observed definitive evidence of water ice in the darkest and coldest parts of Polar Regions of the Moon.
• At the southern pole, most of the ice is concentrated at lunar craters, while the northern pole’s ice is more widely and lightly spread.
• The ice deposits are patchily distributed and could possibly be ancient.
• Most of the newfound water ice lies in the shadows of craters near the poles, where the warmest temperatures never reach above minus 156 degrees Celsius (-250 degrees Fahrenheit).
• Due to the very small tilt of the Moon’s rotation axis, sunlight never reaches these regions.

Importance of the discovery:

• Previous observations indirectly found possible signs of surface ice at the lunar South Pole, but these could have been explained by other phenomena, such as unusually reflective lunar soil.
• Learning more about this ice, how it got there, and how it interacts with the larger lunar environment will be a key mission focus for NASA and commercial partners, as humans endeavour to return to and explore the Moon.
• This brings scope for presence of surface water accessible as a resource for future expeditions to explore and even stay on the Moon.