Thursday, September 24, 2009

Water found on moon

Three different space probes found the chemical signature of water all over the moon's surface, surprising the scientists who at first doubted the unexpected measurement until it was confirmed independently and repeatedly WATER particles have been detected on the surface of the Moon by three missions, including an Indian probe.

two other probes detected water
TWO other probes equipped with M3-type instruments also detected the chemical signature for the presence of water. These include data gathered by the American spacecraft Cassini as it passed near the moon a decade agon on its way to Saturn.

The evidence, disclosed in new scientific papers, overturns the long accepted view that lunar soil is dry and comes just two weeks before a Nasa probe is to crash into the surface near the Moon's southern pole to see if water can be detected in the dust and debris released by the impact.

The new data was gathered by probes equipped with Nasa instruments designed to map the Moon's mineral composition. The so-called 'Moon Mineralogy Mapper', or M3, uses the reflection of sunlight off the Moon's surface to determine soil composition.

In one of the three papers published in the latest edition of the journal Science, researchers said they analysed light waves detected by an M3 instrument on board an Indian satellite, Chandrayyan-1. The reflected light waves indicated a chemical bond between oxygen and hydrogen - proof, the researchers said, of the existence of water on the Moon's surface.

Professor Larry Taylor of the University of Tennessee, one of the study's co-authors, said the instrument is capable of detecting the composition of the thin upper layer of the Moon's surface only to a depth of two or three inches.

Until now, scientists had advanced the theory that there might be ice at the permamently dark bottom of craters at the Moon's poles but that the rest of the Moon was totally dry. Lunar rocks and soil contain about 45 per cent oxygen, but the source of the the hydrogen observed by the instruments on the three probes remains to be determined.

Prof Taylor and his colleagues believe it may have come from an astronomical phenomenon called the solar wind, which consist mainly of streams of positively charged hydrogen atoms emitted as the sun undergoes nuclear fusion. They estimate that each ton of lunar soil consists of 25 per cent water.

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