And again - there is no water on the moon

The Japanese spacecraft Kagoya, orbiting the moon searched and searched and did not find significant amounts of water that could satisfy the needs of a colony on the moon * The pendulum is now moving in the negative direction

The popular assumption was that there are significant amounts of water ice on the moon, hidden from the scorching sun in shadowy craters. One of these craters is Shackleton Crater, which houses the lunar south pole, and previous missions that orbited the moon indicated that it may contain a large reservoir of ice that would supply the needs of a future lunar colony.

However, the Japanese spacecraft Kagoya (and in English SELENE - an acronym for Selenological and Engineering Explorer) took measurements and photographed the interior of the crater and found nothing. At least it failed to detect significant amounts of ice on the surface, what does this mean for planned lunar colonies?

It all started in 1994, when the American spacecraft Clementine (which was shared by NASA and the Ballistic Missile Defense Organization) carried a bistatic radar experiment ("Bistatic Radar Experiment"), which combined the return of radio signals coming out of the transmitter from the polar regions of the moon. The returned signal was received by NASA's Deep Space Network antennas. The scientists who analyzed with him determined that volatile ice is present on the lunar surface, almost certainly in the form of water ice. However, this claim was challenged after a similar experiment was performed using the radio telescope in Arecibo, Puerto Rico. This time, the area from which the radio waves were returned was bathed in sunlight, where ice cannot survive for even a short time, and results similar to those of Clementine were found.

In 1998, NASA's Lunar Prospector spacecraft transmitted mixed results using a Neutron Spectrometer (NS) instrument. The spacecraft discovered 3 billion tons of water ice near the surface of the moon in the polar regions. However, the mission ended in 1999, and the Lunar Prospector spacecraft crashed into the crater at the south pole of the moon in hopes of blowing a plume of material from the surface and discovering the ice in observations from Earth. Unfortunately, no water was detected in this experiment. The LCROSS spacecraft that will reach the moon in April 2009 (together with the lunar probe LRO), will be sent specifically for this purpose - and will crash on the surface of the moon on purpose, so that the observations will be made both from the Earth and from the spacecrafts orbiting the moon, primarily LRO.

The Japanese spacecraft Kagoya took advantage of an opportunity that came its way to take a closer look at Shackleton Crater, the most likely candidate to hold a supply of water shaded from the sun. Because the moon has no atmosphere, except for a negligible amount of life-extending chemicals, sunlight cannot diffuse into the crater floor and illuminate the surface. However, the scientists took the picture in the middle of the southern lunar summer, when enough light reaches the upper part of the crater walls and illuminates the darkness below with a pale light.

Although it is very cold inside the crater (minus 180 degrees Celsius), excellent conditions for keeping the ice there is no visual evidence of the existence of ice on the surface. The Japanese team concluded that there is nevertheless ice mixed in small amounts in the lunar dust, or that there really is no ice there at all. This will probably be discovered by members of a manned expedition in a few decades.