In recent months, some studies have been published suggesting that the interior of the Moon contains more water than scientists have previously thought. However, a new analysis of lunar samples collected during NASA’s Apollo missions indicates thatthe Moon has essentially no water at all.
The team led by researcher Zachary Sharp, from the University of New Mexico (Albuquerque, USA), has measured the composition of thechlorine isotopes in those lunar volcanic rocks, and found that the range of chlorine isotopes contained in the samples was 25 times greater than that found in rocks and minerals on Earth and in meteorites.
Since chlorine is very hydrophilic (attracted to water), it is an extremely sensitive indicator of hydrogen levels. The team suggests that if the lunar rocks had had initial hydrogen contents similar in any way to those of Earth’s rocks, then the fractionation of chlorine into so many different isotopes would never have occurred on the Moon. In light of this finding, Sharp and his colleagues conclude thatthe interior of our satellite is “anhydrous”, that is to say, basically without water, as the scientific community has been proposing for a long time.
The researchers suggest that recent calculations of high hydrogen contents found in some lunar samples are not typical, and that those samples are likely the product of certain igneous processes that resulted in extremely volatile enrichment. The team notes that, in any case, they do not represent the high and variable isotopic values of chlorine found in most lunar rocks.
