A new analysis of lunar rock samples has shown that the likelihood of the presence of water reserves on the moon is small. This conclusion is consistent with popular hypotheses of the formation of an Earth satellite.
The first evidence of the presence of water in lunar rocks became known in the 1970s. Its inclusions were found in rock samples brought to Earth by the astronauts of the Apollo 15 and Apollo 17 missions. Since then, there have been discussions about the amount of this water. According to recent work by scientists from Brown University, the bowels of the satellite are full of water: analysis has shown its presence in samples collected by several missions.
The authors of the new study, published in the journal Proceedings of the National Academy of Sciences, are ready to argue with these findings. According to the results of their analysis of samples, there are exclusively dry rocks in the bowels of the moon.
Scientists examined sample number 66095, which experts informally call "rusty stone" (Rusty Rock). It is one of the lunar samples richest in volatile compounds. He arrived on Earth with the Apollo 16 mission in April 1972. Found it in the area of Stone Mountain.
Surface of "rusty stone", NASA
Using inductively coupled plasma mass spectrometry, the researchers measured the various isotopes of zinc, strontium, rhenium, and osmium in the sample. Scientists have concluded that the "rusty" surface of the stone is rich in light zinc isotopes. According to geochemist James Day, this result supports the view that the Moon was formed as a result of a catastrophic collision of a young Earth with a large cosmic body. Proponents of this theory believe that the moon arose from the debris of colliding bodies.
With such a development of events, the torn off "piece" of the Earth would be very hot, and at high temperatures it would quickly lose volatile substances, including water and light zinc isotopes. According to Day and his colleagues, this is exactly what happened: heavy isotopes of various elements remained in the inner rocks of the satellite, water evaporated, and light zinc isotopes "settled" on the surface during the formation of the moon.
Scientists are planning further studies of lunar rock samples. Information about the amount of water in them will help to establish how exactly the Earth's satellite was formed.
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The research is published in the journal Proceedings of the National Academy of Sciences.
Natalia Pelezneva