By IANS,
Bangalore : India’s Chandrayaan-1 has begun its journey to the Moon -eagerly to find water on its surface – but there is a disappointing news from the Japanese lunar explorer Selene that has been circling the Moon for about a year.
Scientists, who are operating Selene, say that new images taken by a stereo camera onboard the spacecraft indicate that there may not be water or ice in Shackleton crater, the most likely place on Moon that was thought to have water.
The findings were published online Thursday by the American journal Science.
The inside of the Shackleton crater at the Moon’s south pole is a permanently shadowed area, unexposed for the most part to sunlight and, therefore, a place where water-ice deposits have been inferred to exist.
Based on a model of the crater’s shape, the authors suggest that temperatures on the crater floor are less than minus 180 degrees Centigrade — cold enough to hold ice.
The spacecraft Selene took the images of the crater during the lunar mid-summer – when enough sunlight is scattered off the upper inner wall of the crater to provide some faint illumination. The terrain camera has a 10-meter resolution.
“But the images reveal no conspicuous brightness that would indicate a patch of pure water-ice. There may be no ice at all, or any ice that exists might be mixed into the soil at low concentrations,” the researchers conclude.
It is to be seen if Chandrayaan-1 will have better luck. Three of its 11 scientific payloads will look for water in the polar regions including the Shackleton crater.
One of them is the High Energy X-ray Spectrometer built by the Indian Space Research Organization (ISRO).
According to ISRO, this is the first planetary experiment to carry out spectral studies at those X-ray energies capable of identifying polar regions covered by thick water-ice deposits.
The other is the Mini Synthetic Aperture Radar (MiniSAR) supplied by the National Aeronautics and Space Administration (NASA) of the US.
According to NASA documents, MiniSAR is mainly intended for detecting water-ice in the permanently shadowed regions of the lunar poles up to a depth of a few meters. It can optimally distinguish water-ice from the dry lunar surface.
The other NASA-supplied payload – Moon Mineralogy Mapper – is an imaging spectrometer. It is mainly intended to assess and map lunar mineral resources but ISRO says “may also help in identifying water-ice in the lunar polar areas”.
If everything goes as planned, Chandrayaan-1 will start hunting for water on the Moon from November end.