Bangalore, Feb 18: Scientists have for long assumed the Moon to be completely devoid of water but a close examination of ancient lunar rocks has revealed that Earth's lone natural satellite was once wet.
Years of research at leading universities in Europe and the United States resulted in this discovery. While analysing some samples picked up by astronauts who went on the Apollo missions back in the '70s, the researchers were amazed to find traces of water in the bright-coloured rocks. The finding came as a major surprise because the rocks were part of the lunar crust.
Till now the conventional thinking has been that the Moon formed when a large celestial body crashed into the Earth billions of years ago. Scientists thought that the early Moon would have been very hot following the massive impact and consequently all the water present there would have evaporated.
Now it appears that the aforementioned lunar formation theory is not entirely correct. Incidentally, no 'liquid' water whatsoever has been found in the lunar rocks. Instead, hydroxyl groups were detected in a mineral called plagioclase feldspar that is believed to have crystallised from the ocean of magma on the early Moon.
Youxue Zhang, one of the persons involved in the research, said that they stumbled upon "hydroxyl groups distributed within the mineral grain".
Since the Apollo astronauts brought back rocks comprising mainly plagioclase feldspar from the lunar highlands, the scientists are sure that there was water on the early Moon.
"Because these are some of the oldest rocks from the Moon, the water is inferred to have been in the Moon when it formed. That is somewhat difficult to explain with the current popular moon-formation model, in which the Moon formed by collecting the hot ejecta as the result of a super-giant impact of a Martian-size body with the proto-Earth," Zhang noted.
"Under that model, the hot ejecta should have been degassed almost completely, eliminating all water," he added.
OneIndia News (with PTI inputs)