Saturday, September 26, 2009

Does water really exists on the Moon surface?

It is very early to predict about water on the moon.
Dr. Nitish Priyadarshi
Fig.1. Image Credit: ISRO/NASA/JPL-Caltech/Brown Univ./USGS

Answer may be No! The tests on moon rock that has reached earth, either from meteorites or from rock brought back by astronauts, have brought a new meaning to the word dry!

NASA's Moon Mineralogy Mapper, an instrument on the Indian Space Research Organization's Chandrayaan-1 mission, took this image of Earth's moon. It is a three-color composite of reflected near-infrared radiation from the sun, and illustrates the extent to which different materials are mapped across the side of the moon that faces Earth.Small amounts of water were detected on the surface of the moon at various locations. This image illustrates their distribution at high latitudes toward the poles.Blue shows the signature of water, green shows the brightness of the surface as measured by reflected infrared radiation from the sun and red shows an iron-bearing mineral called pyroxene.
It is giant leap for India’s space programme and the biggest scientific discovery of the 21st century. India’s maiden moon mission, Chandryaan-1 has found water, a discovery that scientists say will up-end thinking about space and boost research.
The first object in the night sky most of us ever saw, the Moon remains a mystery. Haunted by poets, looked upon by youngsters in love, studied intensely by astronomers for four centuries, examined by geologists for the last 50 years, walked upon by twelve humans, this is Earth's satellite.
And as we look towards the Moon with thoughts of setting up a permanent home there, one new question is paramount: does the Moon have water? Although none has been definitely detected, recent evidence suggests that it's there.
Is it true? Seeing the early analytical report of the moon rock samples, it is very early to predict about water on the moon.
The Apollo missions (1969-1972) place a number of instruments on the Moon and brought back 382 kg of lunar rocks. The Russian Luna programme also returned samples.
According to the analysis reports on the samples, moon bear many similarities to rocks on earth, they differ on one basic point –they contain no water, no hydrated minerals, and no minerals with OH groups in their crystal structures. In contrast, minerals that are hydrated or contain the OH group are plentiful on earth.

Fig.2 A close-up view of Apollo 15 lunar sample no. 15415 in the Lunar Receiving Laboratory (LRL).

Fig.3. Apollo 16 astronaut Charles Duke collects rock samples near Plumb crater on the Moon.

"Compared with terrestrial samples, all lunar rocks are oddballs because they are so dry," said Ryder a researcher. "They contain no molecules of water, they're not oxidized and they contain no ferric iron. They're easy to distinguish from rocks on Earth."
All rocks collected are igneous - formed by cooling lava. The mission failed to find any sedimentary rocks - those deposited by water - on the moon. The moon rocks were found to contain no water and were formed in an environment lacking free oxygen. Iron then occurs as crystals of metallic iron. Exposure to Earth's atmosphere would result in the rocks rusting. A new mineral, Armalcolite, was found by the Apollo 11 astronauts. It was later discovered on Earth.
The other report also supports saying that the lunar surface being free of water (as liquid) there are no water transported sediments on it.
The moon is a small planet that cooled quickly and has been geologically quiet for billions of years. There are no volcanoes and no earthquakes; there is also no atmosphere to cause weathering and erosion. The Moon is at the same mean distance from the Sun as Earth. But because it does not have the thermal protection of an atmosphere its surface temperature ranges from a searing 125 degree C at the lunar noon to a chilling -160 degree C during the lunar night. Having such a variation in temperatures it is very hard to believe the presence of water in any form on the surface of the Moon. On the earth ponds and lakes generally gets dry when temperature rises up to 40 degree C and remains for few days. How can we imagine that in such a high temperature water molecules can be found even in form of soil moisture on the surface of the Moon. Lacking an atmosphere, the Moon lost almost all of this water when the molten rock spewed onto the surface and cooled.
Other theory says that since it has only a tiny fraction of Earth's gravity, most of the Moon's water supply should have evaporated and drifted off into space long ago.

If the water is really present on the moon surface the process by which the water exists means that it likely also exists on other similarly dry bodies like Mercury and the countless asteroids in the Asteroid Belt between Mars and Jupiter and also it could only be found deep inside the moon.

According to a news published by Press Trust of India (PTI), dated Jun 15, 2009, ISRO Chairman G. Madhavan Nair said that no trace of water was found on the Moon's surface. "But, we have found traces of magnesium and calcium." How the statement has now changed?


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