Water on Moon.. Latest Surprise from Scientists

Scientists posted some surprising findings today about the moon.

The British Guardian reported that the scientists at Nasa’s ASA Goddard Space Flight Center in Maryland, US, gathered some of the most compelling evidence yet for the existence of water on the moon – and it may be relatively accessible.

"The discovery has implications for future missions to the moon and deeper space exploration," the newspaper wrote.

With no significant atmosphere insulating it from the sun’s rays, it had been assumed that the moon’s surface was dry – until the 1990s, when orbiting spacecraft found indications of ice in large and inaccessible craters near the moon’s poles.

Later on, in 2009, imaging spectrometers onboard India’s Chandrayaan-1 spacecraft recorded signatures consistent with water in light reflecting off the moon’s surface.

The technical limitations, however, make it still impossible to know if this really was H2O (water) or hydroxyl molecules (consisting of one oxygen atom and one hydrogen atom) in minerals.

Now, Casey Honniball at ASA Goddard Space Flight Center, and colleagues have detected a chemical signature that is unambiguously H2O, by measuring the wavelengths of sunlight reflecting off the moon’s surface.

The data was gathered by the Stratospheric Observatory for Infrared Astronomy (Sofia), a modified Boeing 747 carrying a 2.7-metre reflecting telescope.

The water was discovered at high latitudes towards the moon’s south pole in abundances of about 100 to 400 parts per million H2O.

“That is quite a lot,” said Mahesh Anand, professor of planetary science and exploration at the Open University in Milton Keynes. “It is about as much as is dissolved in the lava flowing out of the Earth’s mid-ocean ridges, which could be harvested to make liquid water under the right temperature and pressure conditions.”

The existence of water has implications for future lunar missions, because it could be treated and used for drinking; separated into hydrogen and oxygen for use as a rocket propellant; and the oxygen could be used for breathing. “Water is a very expensive commodity in space,” said Anand.

However, harvesting it from dark, steep-walled craters where the temperature rarely climbs above -230C – which is where the bulk of any frozen water was assumed to lie – would be a perilous undertaking. “If it turns out that there is a lot of water in these non-permanently shadowed areas, then that is potentially a very large area, and it is accessible because it is in sunlight,” said Ian Crawford, professor of planetary science and astrobiology at Birkbeck, University of London.

The reason for which the water exists, remains, however. One possibility is that it is dissolved within lunar “glass”, created when meteorites hit the moon’s surface. "Alternatively, tiny ice crystals could be distributed between grains of lunar soil. The latter would be far easier to extract," said Anand.

Another is how deep this newly confirmed water source extends. "If it were restricted to the uppermost few microns or millimetres, then its practical significance would be minimal – although it would still beg interesting scientific questions about how it got there," Prof Crawford said.

British scientists are also developing a robotic drill to take samples of lunar soil from depths of up to a metre, as part of a Russian mission scheduled for 2025.