Water found on the moon – what will it mean for the future?
By Jude Garvey
September 24, 2009
Newspapers and websites around the world are buzzing with the news that water and hydroxyl (hydrogen and oxygen) molecules have been found in the polar regions of the moon. NASA announced yesterday that instruments aboard three separate spacecraft revealed that water molecules were present, although in relatively small amounts. It was also discovered that hydroxyl also existed in the lunar soil. Although the amount of water found is small, it is exciting in terms of potential for the possibilities of establishing a lunar base and even for creating spacecraft fuel.
The data from a remote sensing instrument aboard Chandrayaan-1, India's first mission to lunar orbit, together with data obtained earlier from NASA's Cassini and Epoxi spacecraft missions, confirm that water and hydroxyl molecules are present. The spacecraft carried imaging spectrometers which made the mapping of lunar water more effective than on previous space missions.
When the Apollo missions returned to earth, the soil samples they brought with them were found, when examined in the laboratory, to be slightly “damp”. However, at the time, scientists were not confident that the water did not enter the samples on return to Earth.
"Water ice on the moon has been something of a holy grail for lunar scientists for a very long time," said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. "This surprising finding has come about through the ingenuity, perseverance and international cooperation between NASA and the India Space Research Organization."
Chandrayaan-1 carried NASA's Moon Mineralogy Mapper, or M3 spectrometer. This instrument measured the reflective light from the lunar surface at infrared wavelengths which revealed new detail in the moon’s surface composition. When the data was analyzed, it revealed that the light wavelengths being absorbed showed an absorption pattern that was consistent with those of water and hydroxyl molecules.
"For silicate bodies, such features are typically attributed to water and hydroxyl-bearing materials," said Carle Pieters, M3's principal investigator from Brown University, Providence, R.I. "When we say 'water on the moon,' we are not talking about lakes, oceans or even puddles. Water on the moon means molecules of water and hydroxyl that interact with molecules of rock and dust specifically in the top millimeters of the moon's surface.”
Scientists believe that the water may be created as a result of the soil interacting with solar wind. A chemical reaction is triggered due to the space radiation, and the oxygen in the lunar soil attracts hydrogen nuclei to create water and hydroxyl.
Professor Taylor, a researcher at the University of Tennessee, Knoxville, said, "If it is a little or a lot, it's easy enough to split into hydrogen and oxygen and then you have rocket fuel."
Given the need for finding new sources of water, this discovery is heartening. However, these molecules of water are bound to rock and dust molecules, so scientists would have to find a way of extracting the water. This could be a costly and technically difficult process. So, what will it mean for the future? Will astronauts be able to set up a base camp on the moon and will it be actually possible, in future years, to harness lunar water for fuel?