It seems every few weeks there’s another news story discussing whether there’s water on Mars. But what about the Moon?
NASA has made clear its intentions to send humans back to the Moon in the near future. NASA's new Vision for Space Exploration describes a long-term strategy of returning to the Moon as a step toward Mars and beyond.
Because it is nearby and accessible, NASA scientists believe the Moon is a good place to try out new technologies critical to living on alien worlds before traveling farther into the solar system.
Whether a moonbase will turn out to be feasible depends largely on the question of water. Water for drinking. Water to grow plants. Water that can be broken down to make air (oxygen) and rocket fuel (oxygen+hydrogen).
What’s more, scientists contend, water is surprisingly effective at blocking space radiation. Surrounding the base with a few feet of water would help protect explorers from solar flares and cosmic rays, they explained.
Of course, carrying large amounts of water from Earth to the Moon would be cost prohibitive. Settling the Moon would be much easier if water were already there.
That’s why NASA plans to send a robotic scout. The Lunar Reconnaissance Orbiter, or "LRO" for short, is scheduled to launch in 2008 and to orbit the Moon for at least one year. Carrying various scientific instruments, LRO will map the lunar environment in far greater detail than ever before.
"This is the first in a string of missions," says Gordon Chin, project scientist for LRO at NASA's Goddard Space Flight Center. "More robots will follow, about one per year, leading up to manned flight" no later than 2020.
Astronomers believe that comets and asteroids hitting the Moon eons ago left behind some water. (Earth may have received its water in the same way.) However, water on the Moon cannot last long; it evaporates in sunlight and drifts off into space.
Only in deep, cold craters could one expect to find any water, frozen and not readily apparent. And there just may be deposits of ice hidden deep within craters.
In the 1990s, two spacecraft -- Lunar Prospector and Clementine -- found signs of ice in craters near the Moon's poles, perhaps as much as much as a cubic kilometer. The data were not conclusive, however.
LRO's much more advanced instruments will be used for far more extensive research. They'll map and photograph the Moon in detail, sample its radiation environment and, of course, search for water.