Scientists discover water on Moon's oldest rocks

The new findings indicate that the early Moon was wet and that water there was not substantially lost during the Moon's formation.

The lunar highlands are thought to represent the original crust, crystallised from a magma ocean on a mostly molten early Moon, according to a University of Michigan study.

Researchers used Infrared spectroscopy to analyse the water content in grains of plagioclase feldspar from lunar anorthosites - highland rocks composed of more than 90 per cent plagioclase.

The bright-coloured highlands rocks are thought to have formed early in the Moon's history when plagioclase crystallised from a magma ocean and floated to the surface.

The infrared spectroscopy work detected about 6 parts per million of water in the lunar anorthosites.

"The surprise discovery of this work is that in lunar rocks, even in nominally water-free minerals such as plagioclase feldspar, the water content can be detected.

"It's not 'liquid' water that was measured during these studies but hydroxyl groups distributed within the mineral grain," researcher Youxue Zhang said in a statement.

"We are able to detect those hydroxyl groups in the crystalline structure of the Apollo samples," said study's first author Hejiu Hui from the University of Notre Dame.

The hydroxyl groups the team detected are evidence that the lunar interior contained significant water during the Moon's early molten state, before the crust solidified, and may have played a

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