Tag Archive for James Greenwood

Gilmore, Greenwood, Martin ’14, Dottin ’13 Attend Planetary Science Conference

At left, James Dottin '13 and Peter Martin '14 reunited at the Lunar and Planetary Science Conference in March. Both presented papers at the annual conference.

At left, James Dottin ’13 and Peter Martin ’14 reunited at the Lunar and Planetary Science Conference in March. Both presented papers at the annual conference.

Two faculty, one student and one alumnus made paper presentations at the 45th Lunar and Planetary Science Conference in The Woodlands, Tex., March 17-21.

The Planetary Science Conference brings together international specialists in petrology, geochemistry, geophysics, geology and astronomy to present the latest results of research in planetary science. The five-day conference included topical symposia and problem-oriented sessions. During the conference, Marty Gilmore, chair and associate professor of earth and environmental sciences, presented a paper on the “Venus Exploration Roadmap to the Venus Exploration Analysis Group (VEXAG)” on March 20.

James Greenwood, assistant professor of earth and environmental sciences, presented “Hydrogen Isotopes of Water in the Moon: Evidence for the Giant Impact Model from Melt Inclusion and Apatite in Apollo Rock Samples,” on March 19.

Peter Martin '14 presented a poster titled "Modeling and Mineralogical Analyses of Potential Martian Chloride Brines."

Peter Martin ’14 presented a poster titled “Modeling and Mineralogical Analyses of Potential Martian Chloride Brines.”

Peter Martin ’14 presented his research on “Modeling and Mineralogical Analyses of Potential Martian Chloride Brines” on March 20.  Martin’s travel to the conference was funded by a Connecticut Space Grant and a USRA Thomas R. McGetchin Memorial Scholarship Award. Gilmore is Martin’s advisor.

James Dottin ’13, who is currently a Ph.D. student in geology at the University of Maryland,  spoke on “Isotope Evidence for Links between Sulfate Assimilation and Oxidation of Martian melts from Meteorites MIL 03346, MIL 090030, MIL 090032 and MIL 090136” on March 21.  While at Wesleyan, Dottin participated in the McNair Program. Greenwood was Dotton’s advisor.

Gilmore also presented a paper on “Are Martian Carbonates Hiding in Plain Sight? VNIR Spectra of Hydrous Carbonates,” which was co-authored by Patrick Harner MA ’13. Harner is a Ph.D. student at the Lunar and Planetary Laboratory at the University of Arizona. Harner completed this research while a student at Wesleyan.

Greenwood’s Study Published in Science

James “Jim” Greenwood, assistant professor of earth and environmental sciences, and four colleagues have co-authored a paper titled “The Lunar Apatite Paradox,” published in the  journal Science on March 20. 

The study casts doubt on the theory of abundant water on the moon while simultaneously boosting theories around the creation of the moon, several billion years ago.

NASA Funds Greenwood’s Lunar Rock Study

Jim Greenwood

James Greenwood, research associate professor of earth and environmental sciences, received a grant worth $494,517 from NASA. The grant will support his research titled “Water in Lunar Rocks: Petrologic and Isotopic Analyses of Phosphate Minerals in Apollo’s Samples” through June 30, 2014.

Greenwood Mentioned on BBC News Regarding Water in Lunar Rocks

James Greenwood, visiting assistant professor of earth and environmental sciences, was mentioned in a June 14 BBC News science article on “Much More Water Found in Lunar Rocks.”

Greenwood and Professor Lawrence Taylor from the University of Tennessee in Knoxville, have come up with evidence on the origins of lunar water: comets. According to the article, they believe there were a lot of comets flying around at the time of the Moon’s formation, “hitting the little, nascent, early Moon some 4.5 billion years ago.”

Greenwood Finds Water in Moon Rocks

Jim Greenwood, research assistant professor of earth and environmental sciences, holds a slide with a moon rock sample that contains water. The water was found in the mineral apatite, which he and his team were able to identify in the sample. (Photo by Olivia Bartlett Drake)
Jim Greenwood, research assistant professor of earth and environmental sciences, holds a slide with a moon rock sample that contains water. The water was found in the mineral apatite, which he and his team were able to identify in the sample. (Photo by Olivia Bartlett Drake)

Soon after the Apollo spaceflights to the moon, experts examined the rocks brought back by the astronauts and declared with certainty that the moon was a dry, waterless place.

Forty years later, James Greenwood begs to differ. Not only does he have proof, his findings strongly suggest that some of the lunar water he found is not indigenous to the moon or earth but appears to have originated from somewhere else in space.

Greenwood, research associate professor, visiting assistant professor, Earth and Environmental Sciences, pioneered a new method of analyzing the rocks using a combination of light, electron and ion-beam microscopes. He and his international team of planetary geologists and geochemists, announced their findings at the 41st Annual Lunar and Planetary Science Conference in Houston, Texas, in March.

It was a discovery almost didn’t happen, however. In fact, the only reason Greenwood found proof of water on the moon was because he was looking at a rock from Mars.

“I was in a lab at Hokkaido University in Sapporo, Japan, using an ion microscope to measure water in Martian meteorites,” Greenwood, who is a planetary geochemist, says. “We had pioneered this new technique to use two-dimensional ion imaging and were looking at this mineral in the meteorites called ‘apatite,’ which is a common phosphate mineral and holds water. Our analyses had been very good, probably better than ever before. So I thought, ‘What if we used this technique on moon rocks?’”

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Greenwood thought of moon rocks because a 2008 study from Brown University had found possible evidence of water in volcanic moon rocks. However, the study had been problematic and its results disputed. Still, Greenwood was intrigued that the possibility of water in the lunar rock samples had not been thoroughly vetted.

“The rocks were all declared devoid of water when they were first analyzed 40 years ago,” he said. “But I thought our new technique held some promise.”

Greenwood’s technique and the advanced instruments he gained access to, made it possible for him and the other scientists on his team to analyze the sample’s chemical composition over areas as small as 5 x 5 microns.

“In the past, they had actually ground up the analyzed samples. This created conditions that put the chemical analysis out of context,” he says. “Our method let us look at the samples as they are, in situ.”

The hardest part was getting permission to examine a sample. Less than 900 rocks were brought back from all the Apollo missions combined. Access is strictly limited.

It took several months, but Greenwood was able to get a few samples to analyze. The first were from the lunar highlands, which he thought might hold promise. But no water-holding apatite was found. Then he gained access to a sliver of rock brought back from the southwestern edge of the Mare Tranquillitatis – the “Sea of Tranquility” – where Apollo 11 had set down in 1969.

“So there we were in the lab at about 3 a.m. and the first sample we looked at, boom, there it was. Water. At first we couldn’t believe it. But we double-checked and we were just blown away. It was clearly there.”

The apatite, which is the same mineral that teeth are made of, was rife with water molecules. However, as Greenwood and his colleagues continued to analyze the samples they found that the water contained in the rocks was not from the earth or the moon.

“It was consistent in the water that comes from comets,” Greenwood says.

How could he tell? Water molecules found on earth – and those indigenous to the moon, since it was once part of the earth – contain a specific ratio of hydrogen to deuterium, which scientists use as a standard. The water Greenwood has found in some of the lunar samples has nearly twice the deuterium.

“The only things that falls into this range with any consistency are comets,” Greenwood says.

He adds that comets have long been known to hold frozen water and that perhaps as much as 10% of the earth’s water had come from comets, as well.

Microscopic water in minerals inside moon rocks is a tremendous find, but in a practical sense it does not open the door to, say, astronauts extracting this water to use on a lunar base or colony. Greenwood says that process would be too expensive and energy-exclusive with current methods. However, his discovery does open up another possibility.

“The level of water we found in the samples are consistent with the amount of water one would find from the mantle in the earth,” he says. “So there may be a reservoir of water within the mantle of the moon. Somewhat like groundwater here on earth.”

How far within the mantle, how deep below the surface is another challenge for another completely different type of study.

But Greenwood and his team have confirmed what many people have wondered for centuries, perhaps millennia. There is water on the moon.