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?
