Scientists have confirmed the presence of water ice on lunar surface with the help of data obtained by its instrument aboard India’s Chandrayaan-1 spacecraft, which was launched 10 years ago, U.S. space agency National Aeronautics and Space Administration (NASA) said on Aug. 20.
The Moon Mineralogy Mapper (M3) aboard the Chandrayaan-1 spacecraft, launched in 2008 by the Indian Space Research Organization (ISRO), “was uniquely equipped to confirm the presence of solid ice on the Moon,” NASA said in a statement.
A team of scientists led by Shuai Li of the University of Hawaii and Brown University, and including Richard Elphic from NASA’s Ames Research Center in California’s Silicon Valley, used data from the M3 instrument to identify three specific signatures that prove there is water ice at the surface of the Moon.
“M3 collected data that not only picked up the reflective properties we’d expect from ice but was able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapor and solid ice,” the statement added.
Frozen water deposits are present in the darkest and coldest parts of the Moon’s polar regions, according to the analysis of scientists. They also observed the different patterns in the distribution of ice at the southern and northern pole.
“In the darkest and coldest parts of its polar regions, a team of scientists has directly observed definitive evidence of water ice on the Moon’s surface. These ice deposits are patchily distributed and could possibly be ancient. At the southern pole, most of the ice is concentrated at lunar craters, while the northern pole’s ice is more widely, but sparsely spread,” NASA said.
The latest research revealed that most of the newly found water ice lies in the shadows of craters near the poles of moon. Warmest temperatures in those areas never reach above -250 degrees Fahrenheit. Since Moon’s rotation axis has a very small tilt, sunlight never reaches these regions.
Previous observations have also indirectly indicated the possible signs of surface ice at the lunar south pole, but there existed a possibility to explain them by some other phenomena, such as unusually reflective lunar soil.
NASA also shared the hope that this finding may result into an accessible water resource for future explorations on Moon.
“With enough ice sitting at the surface – within the top few millimeters – water would possibly be accessible as a resource for future expeditions to explore and even stay on the Moon, and potentially easier to access than the water detected beneath the Moon’s surface,” the space agency said.
These findings were published in the Proceedings of the National Academy of Sciences (PNAS).
Chandrayaan-1, India’s first lunar mission went on its journey to Earth’s only natural satellite in 2008. The following year, data from M3 instrument was used to announce “unambiguous evidence” of presence of water molecules across the Moon’s surface. Data obtained by ISRO’s mineral mapping instrument hyperspectral imager, which also was aboard the Chandrayaan-1, supported the evidence.
“We want to thank ISRO for making the discovery possible. Moon till now was thought to be a very dry surface with lot of rocks,” NASA had said at that time.
ISRO is now making preparations to launch its second moon mission, Chandrayaan-2, in a few months. It will conduct deeper explorations in Moon’s south polar region.