The Moon may have the same proportion of water as Earth does

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Today, a group of scientists announced that beneath the surface of the Moon there may be as much water as we have on Earth. This revelation could change everything we know about the Moon — and pave the way for lunar colonies in the next twenty years.

The researchers used a special ion probe to analyze samples of volcanic glass dug up from the Moon's surface by the crew of Apollo 17. Water and other volatiles from deep beneath the Moon's surface remain preserved in this glass, and allowed the team of scientists to determine likely water levels in the Moon's mantle. Those levels were 100 times higher than what previous studies found.

If this study holds up, Moon only has as much water as Earth does in a proportional sense - not as much total water, but as much water as the Earth would have in its mantle if it were the same size as the Moon.

In a statement, Case Western Reserve University geologist James Van Orman said:

In contrast to most volcanic deposits, the melt inclusions are encased in crystals that prevent the escape of water and other volatiles during eruption. These samples provide the best window we have to the amount of water in the interior of the Moon.


Added Brown professor Alberto Saal, another geologist who worked on the study:

The bottom line is that in 2008, we said the primitive water content in the lunar magmas should be similar to the water content in lavas coming from the Earth's depleted upper mantle. Now, we have proven that is indeed the case.


Writing in Science, the team asserted:

These volatile contents are very similar to primitive terrestrial mid-ocean ridge basalts and indicate that some parts of the lunar interior contain as much water as Earth's upper mantle.


In other words, we're seeing — at least in this chunk of volcanic glass — something that looks very similar to what we'd expect on Earth. This could change our understanding of how the Moon was formed. Generally it's believed that the Moon broke off from Earth when our planet was hit by a Mars-sized body. But an impact like that wouldn't have left much water behind. Is it possible the Moon was formed in some other way? That's a subject for further research, but the research team notes two possibilities: one, at some point Earth and the Moon may have shared the same "atmospheric envelope;" or two, the sample that the team analyzed might be aberrant and not indicative of a watery mantle all over the Moon.

These findings also shed light on the icy deposits that probes recently found deep in the shadows of Moon craters. Until now, scientists mostly believed that water came from icy meteors smashing into Luna and leaving water behind. Now it seems that this water probably originated on the Moon, and was brought to the surface by magma in volcanic eruptions.


So how will all of this affect our plans for a lunar colony? Obviously, if the mantle is as water-rich as this new research suggests, we'll have a better chance of generating water and oxygen on the Moon for our habitats. Plus, If lunar water is associated with volcanic activity, then that makes NASA's idea to build a lunar colony in one of the Moon's giant magma holes even more attractive.

See the full scientific paper in Science Express