National Geographic News
THIS IS #5944: AS11-40-5943 (OF300) ( 939k or 207k )    110:58:24. Buzz has gone beyond the small crater and is looking for a flat spot on which to put the LRRR. Note the depth of the footprints he has left in the soft rim of the crater. Beyond the crater, where he is standing at this moment, his footprints are only a fraction of an inch deep and are more typical of the footprints that he and Neil normally leave. Note that Buzz has just walked between some rounded, partially-buried boulders, which he mentions at 110:58:24. This picture is the first of a stereopair Neil takes of them.AS11-40-5944 (OF300) ( 980k or 210k )    110:58:24. Neil has stepped to his left to get a stereo companion to 5943. Note the build up of soil on the base of these boulders due to ejecta from the foreground crater. Note that there is another split boulder in this photograph, to Buzz's right. From 5948, we know that Buzz will put the LRRR down northwest of this boulder and the seismometer southeast of it. This means that at some point after 5944, Buzz will move about 10 meters (30 feet) to his right. Figure 3-16 ( 196k re-draft by Thomas Schwagmeier) in the Apollo 11 Preliminary Science Report shows his path from the SEQ Bay out to the deployment area.
Apollo astronaut Buzz Aldrin collects moon rocks in 1969.

Photograph courtesy NASA

Andrew Fazekas

for National Geographic News

Published June 14, 2010

Could this be the final blow to the theory that the moon is bone dry?

Not only does the moon's surface hold a "significant amount" of water—as two NASA crashes confirmed in October—but, a new study says, the moon's interior may hold at least a hundred times more water than previously estimated.

"If we could take all the water which is locked up in the moon's interior, it would make a one-meter-deep [one-yard-deep] ocean covering its entire surface," said lead study author Francis McCubbin, a geologist with the Carnegie Institution for Science in Washington D.C.

McCubbin's team reanalyzed old moon-rock samples gathered by Apollo missions and a lunar meteorite found in a desert in Africa. (Related: "Apollo 11 Hoax Photos: Moon-Landing Myths—Busted.")

The findings indicated that inside the moon "the amount of water is at least 64 parts per billion, which is two orders of magnitude more than previously thought," McCubbin said. "And maybe even more is there."

(Related: There's Water on the Moon, NASA Probes Confirm)

Moon Water Found Hidden in Crystals

Using electron microscopes, McCubbin and his team looked at thin moon rock slices and collected tiny crystal grains of the mineral apatite. Lunar apatite is thought to have formed billions of years ago, when the moon's interior was filled with hot magma.

The team peered into the apatite crystals using a technique called secondary ion mass spectrometry—training a beam of ions on the rocks and then studying the ions that the beam dislodges from the material.

In the process, the researchers stumbled onto something big: the telltale chemical signature of water, in the form of hydroxyl ions.

"Until this study water had never been reported within minerals from the moon," McCubbin said.

Apatite naturally soaks up water as water-bearing magma cools, locking it up in the form of hydroxyl ions—pairs of bonded hydrogen and oxygen atoms.

As such, apatite "really is a natural mineral to look for, because if there was any water in lunar rocks it would end up in that apatite," he said.

(Read more about moon exploration.)

Amount of Moon Water Stuns Scientists

The moon may not be soaking wet—it's still considered drier than the driest desert on Earth. (VIDEO: Crash Course on the Moon.)

But the quantity of water detected by the new study has stunned the scientific community, according to planetary geologist Linda Elkins-Tanton, who isn't connected to the study.

"It's definitely surprising in that they are finding a lot more water in these minerals than would have been predicted," said Elkins-Tanton, an assistant professor at the Massachusetts Institute of Technology (MIT).

"This now shows that primordial water was present when the moon itself formed," she said.

Moon-Water Discovery a Total Game-Changer?

While much has been made of the possibility of using moon water for hydrogen fuel for spacecraft or to sustain moon colonies, even the splashy new estimates are probably too low to make extraction economically viable, Elkins-Tanton said.

The real impact of the new moon-water discovery is in what it might say about the formation and evolution of both the moon and Earth, she said.

The leading theory on the moon's origin says the satellite formed when a Mars-size object collided with Earth 4.5 billion years ago, sending a spray of material out into Earth orbit—material that eventually coalesced, forming the moon. (Read "Was Moon Born From Planet's Crash into Earth?")

All major, current moon-origin computer simulations suggest that the physics are such that the moon likely formed exclusively from the pulverized remains of the impactor—not from bits of Earth.

The big problem with this model, though, is that many isotopic elements found on the moon match elements found on Earth and no other body in the solar system measured so far—suggesting a kinship between Earth and the moon.

So if the moon is made from the impactor, then why would the impactor happen to have the same materials as Earth?

"An extremely unlikely coincidence," she said. "This is why the discovery of water in the interior of the moon is really a critical piece of the puzzle to try and figure out how the Earth and the moon are really linked."

By carefully measuring the water in these lunar minerals and matching up their isotopic ratios with those found on Earth, Elkins-Tanton believes it may lead us closer to solving the mystery of where both the Earth and the moon got their water.

"This," she said, "could be a total game-changer."

Findings to be published Tuesday in the journal Proceedings of the National Academy of Sciences.



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