Water, Water Everywhere… Lunar Samples Show More Water Than Previously Thought


A team of NASA-funded researchers led by Carnegie Institution’s Erik Hauri has recently announced the discovery of more water on the Moon, in the form of ancient magma that has been locked up in tiny crystals contained within soil samples collected by Apollo 17 astronauts. The amounts found indicate there may be 100 times more water within lunar magma than previously thought… truly a “watershed” discovery!

Orange-colored lunar soil sampled during Apollo 17 EVA missions was tested using a new ion microprobe instrument which measured the water contained within magma trapped inside lunar crystals, called “melt inclusions”. The inclusions are the result of volcanic eruptions on the Moon that occurred over 3.7 billion years ago.

Because these bits of magma are encased in crystals they were not subject to loss of water or “other volatiles” during the explosive eruption process.

“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.”

–  James Van Orman of Case Western Reserve University, team member

While it was previously found that water is contained within lunar magma during a 2008 study led by Alberto Saal of Brown University in Providence, Rhode Island, this new announcement is based upon the work of Brown undergraduate student Thomas Weinreich, who located the melt inclusions. By measuring the water content of the inclusions, the team could then infer the amount of water present in the Moon’s interior.

The results also make correlations to the proposed origins of the Moon. Currently-accepted models say the Moon was created following a collision between the newly-formed Earth and a Mars-sized protoplanet 4.5 billion years ago. Material from the Earth’s outer layers was blasted out into space, forming a ring of molten material that encircled the Earth and eventually coalesced, cooled and became the Moon. This would also mean that the Moon should have similarities in composition to material that would have been found in the outer layers of the Earth at that time.

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

– Alberto Saal, Brown University, RI

The findings also suggest that the Moon’s water may not just be the result of comet or meteor impacts – as was suggested after the discovery of water ice in polar craters by the LCROSS mission in 2009 – but may also have come from within the Moon itself via ancient lunar eruptions.

The success of this study makes a strong case for finding and returning similar samples of ejected volcanic material from other worlds in our solar system.

“We can conceive of no sample type that would be more important to return to Earth than these volcanic glass samples ejected by explosive volcanism, which have been mapped not only on the Moon but throughout the inner solar system.”

– Erik Hauri, lead author, Carnegie’s Department of Terrestrial Magnetism

The results were published in the May 26 issue of Science Express.

Read the full NASA news release here.

17 Replies to “Water, Water Everywhere… Lunar Samples Show More Water Than Previously Thought”

  1. Water, water everywhere, but the pubs on the Moon are dull because they have no atmosphere!

    Um… I’ll get my coat and see myself out…

  2. may more water can there, without gravity and air how come life is possible there?

    1. Life is possible on the moon because it stays strictly inside a space suit and only hangs about for a short period of time before going home.

      Also, it’s not true to say “without gravity” – traces of gravity have been detected on the moon for quite some time.

    2. Life _is_ possible from this, since we know have plenty (well, more than an insignifican amount) of volatiles in the rocks and a molten core supplying heat, both results courtesy of the Apollo project. Volatiles could be locally concentrated. The rocks could provide the chemical energy required for abiogenesis, and harbor a potential biosphere at a Goldilocks zone somewhere between the core and the surface.

      This may be a better bioenvironment than the same speculations on the soon to be visited Ceres, since the larger Moon mass would make the zone stabler and less movable & shrinking over time. (The Moon mass ~ 100 x Ceres.)

      The Moon mass, btw, which supplies a not insignificant surface gravity of some 1/5 of Earths.

      Whether gravity is a requirement for life is arguable. Cells survive in micro-gravity environments for prolonged periods (as the astronauts show) and all the forces that are believed to form protocells would be present. The larger problem with speculating on the hypotheses of life without gravity is that without rocks & volatiles, no chemistry – but with rocks & volatiles, some gravity.

      1. Er… dude, the Moon’s equatorial surface gravity is 1.622 m/s2, which is 16.54%, or about 1/6, of the Earth’s gravity.

      2. IVAN, I think you missed the descriptor, “some” 1/5, although you’re technically correct, as 16.5% is much closer to 1/6 than the 20% that Torjorn used.

      3. Yeah, you’re right; instead, I’ve placed Torbjörn’s incorrectly stated figure within a pair of double quotation marks.

        Oh, er… you’ve missed out the letter “b” in Torbjörn’s name; I think that you should fix it before you incur his displeasure. =^..^=

      4. Er….you are correct sir. I seem to have a problem spelling his name…..Sorry Torbjorn, no offense meant!

      5. No offense taken! Foreign names are always a problem.

        The worst part occurs if you have to ask repeatedly before starting to sort out the sounds. Sometimes you want to go “can you repeat that backwards too, please”…

      6. Yeah, you’re right; instead, I’ve placed Torbjörn’s incorrectly stated figure within a pair of double quotation marks.

        Oh, er… you’ve missed out the letter “b” in Torbjörn’s name; I think that you should fix it before you incur his displeasure. =^..^=

      7. “Do you want your gravity light or sugared?”

        Dude, chill. The Moon is round, ergo I rounded. =D

  3. Good catch! This is great, I assume a really good test of the Earth-Moon impactor theory,* and hopefully a better constraint on volatiles delivered to Earth.

    IIRC the Moon reforms quickly in the models, so very little time for photo ionization by the young sun and subsequent hydrogen escape from Earth’s gravity well. That the bulk of the water stays make much more sense. So it should confirm even details of the great impactor theory.

    * But also: sigh! There goes my year ‘old’ astrobiology refs, which has the discrepancy in volatile content as a mystery to solve. Already dated.

  4. I wouldn’t say it’s a good test of the Earth impact theory, although it does add its points to the theory, such an impact would deplete any water and volatile elements due to the heat and violence of the impact. So the moon inherited these elements on its own through comet impacts and other processes or the formation of the Moon was different all together. That’s just my opinion though.

  5. The early stellar nebula/nursery must have been pretty wet, which of course… I LIKE!

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