Within about two weeks, a powerful missile will be shot into craters in the moon's poles to raise dust for determining whether there is water - in the form of ice - inside. If so, it could supply oxygen for breathing, water for drinking and hydrogen for fuel in a future lunar outpost in the next decade or two.
Launched last June from Florida by the US National Aeronautics and Space Administration, the Lunar Reconnaissance Orbiter (LRO) unmanned mission was meant to map the entire moon comprehensively. But one of its most critical missions is to survey for the first time the temperature of the lunar surface and determine whether there is water ice in the craters. The year-long mission of the Lunar Crater Observation and Sensing Satellite is to examine areas that have never been viewed before and that certainly have never been visited in person by astronauts on NASA space vehicles.
The parts of the moon that will be examined are the coldest in our solar system (even colder than on Pluto, the most distant planet) - areas so deep that their shadows have never been illuminated by the sun, says Dr. Noah Brosch, leading astronomer of Tel Aviv University and director of its Wise Observatory at Mitzpe Ramon.
According to Brosch, there have been hints of the existence of ice, but only with a missile explosion inside a polar crater can this be scientifically determined.
"There may be water mixed with thick dust that would make ice invisible even with observation from an unmanned space vehicle above," he said Monday.
Prof. Tsvi Piran of the Hebrew University Racah Institute of Physics added that the spectrum of the dust kicked up by the explosion would be examined when the sun's rays passed through the particles.
"Every material has lines characteristic of the substance," Piran explained. "Certain colors in a rainbow don't appear, and these lines that block them signify what they are composed of. If there are oxygen and hydrogen, we will know it is water."
According to NASA, the spacecraft and the Atlas V's Centaur upper stage rocket will fly by the moon and enter into an elongated orbit to position the satellite for impact. On final approach, the spacecraft and Centaur will separate. The Centaur will strike the chosen lunar crater, creating a debris plume that will rise above the surface. Four minutes later, the unmanned space vehicle will fly through the plume of debris, collecting and relaying data back to Earth before striking the moon's surface and creating a second debris plume.
The lunar poles' temperatures go as low as -370Âº Celsius, so ice could easily form if water were present. At the moon's equator, where NASA's manned Apollo flights have landed, temperatures reach 100Âº Celsius during the day, making ice formation impossible, explained Brosch. Other liquids such as ammonia cannot freeze there, either.
The new mission will look for other things, such as isotopes of helium, that may be in the polar craters as well, he said. If there is frozen water, said the TAU astronomer, "it would be expected. The surprise is that it hasn't been found yet. The question is how much there is. If there are chunks of ice, it will be easier to remove."
Any water found could not be consumed after being melted, he added. "It will be dirty with dust, but no chlorine would be needed to remove germs, as there are none."
According to Piran, if there is water on the moon, it could be separated into oxygen and hydrogen gas.
Water is critical to sustaining a human colony on the Moon. In addition to oxygen, water could be used to grow food, and hydrogen could supply energy.
"There is an international space station, but a permanent colony on the moon could take dozens of years to build," he said. "It would be hugely expensive and require international cooperation."
Piran was not aware of academics from Israeli universities involved in the current NASA project, but he does have an Israeli-born friend in California who is an expert in ice beyond Earth.
The thermal mapping of the moon is being carried out by the Diviner Lunar Radiometer Experiment, which has a spatial resolution of just a few hundred meters. So far, the Diviner instrument has disclosed well-detailed thermal behavior throughout the north and south polar regions. Since the instrument from first activated on July 5, it has acquired more than eight billion calibrated radiometric measurements and has mapped almost 50 percent of the moon's surface area.
The LRO is the first mission in NASA's Vision for Space Exploration program, a plan to return to the moon and then to travel to Mars and beyond. The mission will gather crucial data on the lunar environment that will help astronauts prepare for long lunar expeditions.