Water in the Lunar Interior

1
Water in the Lunar Interior
Francis McCubbin and co-workers measured the OH
concentrations in lunar sample 15404,51
(collected from debris on boulder in the image on
the left) and in lunar meteorite NWA 2977
(right).
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Water in the Lunar Interior
OH in Apatite 220-1000 ppm in 15404,51 4000-7000
ppm in NWA 2977
H2O in lunar interior appears to be 1 to a few
tens of ppm, much higher than previously thought,
lt 1 ppb.
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Implications of Lunar Water Content
Water in the Moon raises questions about its
origin by a giant impact Dynamical calculations
indicate that most of the Moon was formed from
material that resided in the impactor. Did the
impactor contain water? If so, how much? Was
some of it lost as the result of the large
impact? Was a lot or a little lost? Did some
react with silicates in the proto-lunar disk?
Or was the water added later, to both Earth and
Moon? Why does the Moon contain a few parts per
million to a few tens of parts per million water
while the Earth contains much more, 500 to 1000
parts per million?
Canup (2004)