Ancient volcanic deposits on the moon reveal new evidence about the lunar interior, suggesting it contains substantial amounts of water.

Using satellite data, scientists from Brown University studied lunar pyroclastic deposits, layers of rock that likely formed from large volcanic eruptions. The magma associated with these explosive events is carried to the moon's surface from very deep within its interior, according to a study published today (July 24) in Nature Geoscience.

Previous studies have observed traces of water ice in shadowed regions at the lunar poles. However, this water is likely the result of hydrogen that comes from solar wind, according to the new study's lead author, Ralph Milliken, a geologist at Brown University. The new research reveals there is likely a large amount of water in the moon's mantle, as well. This suggests that the water was delivered to the moon very early in its formation, before it fully solidified, Milliken told Space.com. [Photos: The Search for Water on the Moon]

Colored areas on this map show spots with elevated water content compared with surrounding terrain on the moon's surface. Yellow and red indicate the richest water content. (Image credit: Milliken lab/Brown University)

"We observe the water in deposits that are at the surface today, but these deposits are the result of magma that originally comes from deep within the lunar interior," Milliken said. "Therefore, because the products of the magma have water, the deep interior of the moon must also contain water."

The researchers analyzed satellite data from the Moon Mineralogy Mapper instrument aboard India's Chandrayaan-1 probe, which measures reflected sunlight at visible and near-infrared wavelengths. In order to estimate the amount of trapped water in the pyroclastic deposits, the scientists had to isolate the reflected sunlight from the thermal energy emitted by the moon's hot surface.

"Different minerals and compounds will absorb and reflect light in different ways, so in our case we looked at wavelengths where [the molecules] H2O and OH absorb light," Milliken said. "We found that there were larger absorptions, or less reflected sunlight, at these wavelengths for pyroclastic deposits, which indicates they contain OH or H2O."

Previously, scientists from Brown detected trace amounts of water in similar volcanic samples — which are composed of loose material or "glass beads" — brought back to Earth from the Apollo 15 and 17 missions. However, the Apollo samples were not collected from the large pyroclastic deposits mapped using the satellite data in the recent study. This brought into question whether the Apollo samples represent a large portion of the moon's "wet" interior or if they represent only a small water-rich region within an otherwise "dry" mantle.

"Our work shows that nearly all of the large pyroclastic deposits also contain water, so this seems to be a common characteristic of magmas that come from the deep lunar interior," Milliken said. "That is, most of the mantle of the moon may be 'wet.'"

However, the question of how the water got in the moon's interior remains unresolved.

"It is generally thought that the giant impact event that formed the moon was too energetic and hot for water to remain, yet there it is," Milliken told Space.com. "One option is that the water was delivered after the giant impact event, but before the moon had completely cooled, likely due to impacts by water-bearing comets and asteroids."

Evidence of water deep beneath the lunar surface may also have implications for how Earth got its water, scientists say. Furthermore, the study's findings suggest that the pyroclastic deposits could possibly be mined for water, which, in turn, could fuel future missions to the moon.

"These deposits may be much easier to access than potential water ice in shadowed regions at the lunar poles," Milliken said. "Water is heavy and expensive to take from Earth to space, so any bit of water that you can get on the moon instead of bringing with you from Earth is a big deal and opens up possibilities for sustained human presence on the moon."

Going forward, the scientists would like to map the pyroclastic deposits in greater detail so that they can better understand how water concentrations vary among different deposits on the lunar surface. Milliken also noted that these deposits would be great targets for future exploration, during which samples could be collected and later studied to further refine the estimated water content of the moon's interior.

"If humans may go to one of these places, then we want to have the best possible roadmaps and resource maps that we can," Milliken said. "We'll also try to integrate our satellite observations with theoretical models of volcanic eruptions to better constrain our estimates of the amount of water."

"The better we understand how much water is there, then the better we can estimate the processes responsible and the usefulness of the deposits for future human exploration," he added.

Follow Samantha Mathewson @Sam_Ashley13. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.</s>(CNN) There may be water -- a good bit of it -- deep inside the moon, scientists at Brown University say.

By analyzing satellite images, the scientists found evidence of water trapped in "glass beads" in ancient ash and rocks that volcanoes spewed across the surface of the moon, said Ralph Milliken, lead author of the new research, published in Nature Geoscience , and an associate professor in Brown's Department of Earth, Environmental and Planetary Sciences.

"The fact that nearly all of them (the volcanic deposits) exhibit signatures of water suggests ... that the bulk interior of the moon is wet," he said in a news release.

This finding might be a boon for future missions to the moon because water could potentially be extracted from the volcanic deposits, Milliken told CNN.

Though the volcanic glass beads don't contain much water -- maybe a few hundred parts per million -- there's a great deal of the volcanic material to work with, Millliken told CNN. Some fields of this volcanic refuse cover thousands of square kilometers and may be several meters deep, he said.

"It's more water than previously recognized," he said.

Volcanic glass beads

Previous findings of water on the moon didn't appear to come from indigenous sources, Milliken said.

In 2009, NASA announced it had found water on the moon. One ton of the moon's surface might yield 32 ounces, NASA scientists said.

Scientists speculated those crystals might have been created by solar winds that interacted with hydrogen at high altitudes, Milliken said. There are also small amounts of frozen water at the moon's poles, he said.

Scientists believed the moon was dry when the Apollo missions started in the 1960s. That thinking changed in 2008 when volcanic glass beads brought back by the Apollo 15 and 17 missions of 1971 and 1972 were found to contain tiny crystalline formations that contained water, the Brown news release said.

But nobody knew if those Apollo samples represented the whole moon or just unusual spots on an otherwise dry surface, Milliken said.

Scientists at Brown took another look at images of the moon's surface retrieved from the Moon Mineralogy Mapper, an imaging spectrometer that flew aboard India's Chandrayaan-1 lunar orbiter in 2008.

These images showed materials never examined by the Apollo missions. After developing a "thermal correction" that separated the readings of reflected light and heat, scientists were able to collect data showing evidence of the glass beads in nearly all the volcanic deposits spread across the moon, Brown said.

"The distribution of these water-rich deposits is the key thing," Milliken said in the news release. "They're spread across the surface, which tells us that the water found in the Apollo samples isn't a one-off."

The study was funded by NASA.

"The new results from Milliken and Li show that the water is widespread, found in numerous pyroclastic deposits across the lunar surface, suggesting that the lunar mantle has significant amounts of water, not just in a couple of weird pockets," said Sarah Noble, program scientist at NASA Headquarters in Washington. "This implies that either the moon managed to retain significant amounts of water after the giant impact, or that volatile-rich material accreted to the moon (and the Earth as well) soon after the impact.

"Although the amount of water found by the authors is significant in terms of our understanding of the moon and how we model the lunar interior, it is still a very small amount, around 0.015% of the soil."

Is it worth the cost?

Man has not set foot on the moon since the Apollo 17 mission in December 1972. Milliken said the moon could serve mankind, even if we don't want to stay there for very long.

"If we want to send people to Mars, you might consider using the moon as a stepping stone for training or testing equipment," he said. "If you do that you'll need water. It's heavy and expensive to lift off Earth."

But can the water actually be extracted and would it be worth the cost? That's one of the big questions about the discovery, he said.

And how did the water get on the moon in the first place?

Scientists think the moon was created by debris left behind when a planet-sized object slammed into the Earth, Milliken said.

"The growing evidence for water inside the moon suggests that water did somehow survive, or that it was brought in shortly after the impact by asteroids or comets before the moon had completely solidified," Shuai Li, a co-author of the research and a postdoctoral researcher at the University of Hawaii, said in the news release. "The exact origin of water in the lunar interior is still a big question."</s>Scientists who retested mineral samples collected during the Apollo moon missions now believe there’s a massive amount of water under the lunar surface – a discovery which may make manned missions to the moon easier than previously thought.

Researchers at Brown University in the US examined glass beads, a type of volcanic crystal gathered during the Apollo 15 and 17 missions in the 1970s, and found they contained similar volumes of water to Earth’s basalt rock.

The leaders of the study, which has been published in Nature Geoscience, cite the parallels as evidence that parts of the moon contain a similarly large amount of water. This, they believe, could be useful for future lunar missions as it means water could potentially be extracted rather than carried from home.

“Other studies have suggested the presence of water ice in shadowed regions at the lunar poles, but the pyroclastic deposits are at locations that may be easier to access,” said lead author Dr. Shuai Li, formerly of Brown University and now at the University of Hawaii.

“Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative."

Scientists used instruments and images from India’s Chandrayaan-1 lunar orbiter which bounced light off the moon to see which minerals are present.

It was previously thought that water could only be found on each of the moon’s two poles, but deposits of volcanic beads, formed when magma crystallized after rising to the surface, have been found far and wide across the lunar surface.

“The fact that they see this feature associated with the glasses tells us that there was indeed quite a bit of water in the interior of the moon when these volcanic eruptions were occurring,” says Anthony Colaprete, a NASA scientist who reviewed the paper.

The race to create the first manned lunar base has been heating up in recent years.

In April, the European Space Agency announced plans to partner with China on a 'Moon Village,' a 3D-printed cluster of lunar outposts that could one day serve as a stop-off point on a journey to Mars.

Groundwork for the Moon Village mission will begin in November, when China plans to send a probe to the moon to retrieve rock and soil samples. The Chang’e-5 mission will be China’s first ever attempt at sample retrieval in space.</s>But the Apollo moon rocks were only a sample. They could be anomalies, poor representatives of what really lies beneath the surface.

These tiny beads became a lot more interesting in 2008, when scientists discovered they contained water . In 2011, researchers found that the beads contained similar amounts of water as some basalts on Earth, which form when volcanic rock from the planet’s mantle cools rapidly. For decades, scientists had thought the moon was a dry world. The clues inside the glass beads suggested a different story. There’s water on the moon, and some of it may still exist in ancient deposits deep within its interior.

In the 1970s, the Apollo astronauts returned from the moon with tiny beads of volcanic glass they had picked out of the lunar soil. The beads are remnants of the moon’s early history billions of years ago, when eruptions spewed magma onto the surface. The magma, exposed to the vacuum of space, cooled rapidly. Some droplets froze as they fell, hitting the ground as glass.

Ralph Milliken, a professor in Brown University’s geological sciences department, decided to widen the search. Milliken and his collaborator, Shuai Li, a researcher at the University of Hawaii, used satellite data to study numerous volcanic deposits across the lunar surface where water, if it exists, would be contained in glass beads like the ones the Apollo astronauts collected.

“Sure enough, we found it,” Milliken said.

The researchers detected trapped water in dozens of the volcanic deposits, some measuring thousands of square kilometers. These regions also contained far more water than surrounding terrain. The data came from the Moon Mineralogy Mapper, a NASA spectrometer that flew aboard India’s first lunar mission in 2008. The instrument measures the wavelengths of light absorbed or reflected by a surface, which scientists can use to determine the composition of the object. The findings were published Monday in Nature Geoscience.

Milliken said the findings suggest the moon holds significant amounts of water, but it’s difficult to estimate how much. “That’s a very difficult question to answer," Milliken said. “I think it’s hard for the average person to understand what [this] means.” He said his research supports the conclusion from the 2011 study on the beads’ composition, that parts of the moon’s mantle could contain as much water as Earth’s.

Scientists don’t yet know how the moon got the water they've observed, and there are several possible sources. “To me, that’s still one of the biggest questions out there,” Milliken said. Most scientists believe water couldn’t have survived the heat of the violent impact between Earth and a Mars-sized object that created the moon 4.5 billion years ago—but maybe it did, somehow, Milliken said. Water-rich asteroids and comets could have struck the moon early on, when it was still cooling, or later in life. Other research has also shown water may be created on the moon’s surface when hydrogen atoms from solar wind react with oxygen atoms buried in moon rocks.

Whatever the origin, the water-rich deposits on the moon will come in handy for any future thirsty astronauts. “Even though an individual glass bead doesn’t have a lot of water in it, the size of these deposits is enormous, so you have a lot of material to work with,” Milliken said.</s>We've long known that water ice is holed up in the darkest, coldest craters on the moon, but now scientists think the story of lunar water runs much deeper, far below its surface. And this is good news if humanity wants to build that moon base we've been promising ourselves for so long.

Here's the backstory: In 2008, scientists analyzed small glass beads found in the samples of moon rock brought back to Earth by the Apollo 15 and 17 missions in 1971 and 1972. These volcanic beads originated from the moon's interior, and the crystalline structures contained a small, yet surprising amount of water, overturning the idea that the moon's subsurface was largely devoid of water.

More research found that the beads contained similar quantities of water as some basalts on Earth – another clue that the moon was formed from the debris of Earth after a massive ancient impact with another planetary body.

Now, in a new study published in the journal Nature Geoscience, spectroscopic data from the Moon Mineralogy Mapper onboard India's Chandrayaan-1 lunar orbiter was used to map the lunar surface; specifically it sought regions where there are elevated concentrations of water deposits in lunar rock that originated from volcanic activity. And guess what? It looks like the water-rich Apollo samples weren't an anomaly, which is welcome news.

"By looking at the orbital data, we can examine the large pyroclastic deposits on the moon that were never sampled by the Apollo or Luna missions. The fact that nearly all of them exhibit signatures of water suggests that the Apollo samples are not anomalous, so it may be that the bulk interior of the moon is wet," said planetary geologist Ralph Milliken, in the press release. Milliken is the lead author of the new study and works at Brown University.

These spectrometer data were recorded by studying the reflected sunlight bouncing off the moon's surface. Some wavelengths of light are absorbed by certain chemicals, so when the reflected light is received, the Moon Mineralogy Mapper could identify which materials were present. But to tease out the signal of water in the pyroclastic flows, the researchers had to carefully remove the interference of thermal emissions caused by the sun's heating of the daytime surface.

"That thermally emitted radiation happens at the same wavelengths that we need to use to look for water," Milliken said in the statement. "So in order to say with any confidence that water is present, we first need to account for and remove the thermally emitted component."

Using the Apollo samples in tandem with detailed thermal models of the moon's surface, the scientists corrected the map, revealing the distribution of water trapped in these ancient volcanic flows.

As these pyroclastic deposits contain a surprisingly high proportion of water, this likely means the moon's interior contains a lot more water than previously thought, a finding that has huge implications for our theories of how the moon formed. If the moon was formed from the molten debris of a massive Earth impact, how did the hydrogen required in water molecules survive the extreme heating?

"The growing evidence for water inside the moon suggest that water did somehow survive, or that it was brought in shortly after the impact by asteroids or comets before the moon had completely solidified," said co-author and postdoctoral researcher Shuai Li, who works at the University of Hawaii. "The exact origin of water in the lunar interior is still a big question."

There are obvious implications for the future of possible human missions to the moon. If the moon was bone-dry, setting up any form of long-term human presence on the surface would be difficult, possibly unsustainably so. Launching supplies, materials and fuel from Earth to the lunar surface requires powerful and expensive rockets, but if we can source building materials and water from the lunar surface, we may eventually establish a self-sustaining, permanent moon base.

The researchers emphasize that the quantity of water is small – only 0.05 percent of the material by weight is water – but there's a lot of it on or close to the surface with, potentially, a huge supply in the moon's mantle. So, if we do set up a long-duration presence on the lunar surface, perhaps we can develop an efficient water extraction process that could make it sustainable – producing drinking water and fuel, and driving some form of space agriculture.

"Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative," Li concluded.</s>It seems we're always finding water on Mars—but a paper published in Nature Geoscience today reveals more space water much closer to home.

Using data from the Indian Space Research Organisation's (ISRO) Chandrayaan-1 lunar orbiter, two researchers from Brown University found something thought to be long gone: Water on the surface of the moon. But don't expect to go swimming anytime soon; it's trapped in rock.

The researchers specifically focused on pyroclastic rock, which is volcanic in origin. Samples returned from Apollo 15 and 17 showed an abundance of water trapped in glass "beads" within the rock, but researchers have since debated whether these rocks in particular were saturated with water for a unique reason or if all pyroclastic rocks on the moon develop these tiny pockets of water. It now seems that the evidence supports the latter, and pyroclastic rocks all over the moon contain notable stores of water.

"We saw that there were enhanced absorptions in the pyroclastic deposits but not in any of the surrounding terrains," says Ralph Milliken, a professor of planetary science at Brown University. "This was a key indicator that there was something different about these regions and that they were water-bearing relative to other nearby terrains."

Shuai Li, a graduate student at Brown and co-author on the paper, cautions that the water doesn't appear to be in an ice form, but rather is trapped in the minerals. Milliken and Li are also still trying to determine if it's actually hydrogen dioxide or or if it might be hydroxyl, a similar compound made of one hydrogen atom and one ionized oxygen atom. Whether it's water or hydroxyl "cannot be discriminated based on current satellite data," Li says.

There's no evidence that this finding is connected to ice deposits, and Li says that there's "definitely no" oceanic source of the water. But the water or hydroxyl does come from fairly deep below the lunar surface. "This water is inside the glass and originates from deep within the interior of the moon," Milliken says.

The water may be trapped in the lunar rocks, but that doesn't mean we can't use it. "The water signature seen in pyroclastic deposits has significant implications for future exploration of the moon," Li says. "Such water can be used as in situ resources."

Milliken agrees. "Our work shows that nearly all of these large deposits may also have water, and that is one of the most important resources that you would want to be able to have on the moon," he says. "Water is heavy and expensive to get from Earth to space, so any water that you can harvest on the moon gives you a huge advantage."

It also means that any future moon base may not have to rely as heavily on icy deposits at the poles away from the sun. Instead, it's possible to move to warmer latitudes based on the abundance of pyroclastic rock with glass beads of water instead.

"Water ice may be present in shadowed regions at the lunar poles, but the pyroclastic deposits may be much easier to access," Milliken says. "Though they don't have a lot of water in terms of weight percent there is a lot of this material, so it could be feasible to use it as a water resource."

"This is very similar to the mining process on Earth, extracting pure materials from low concentrations," adds Li.

So maybe we shouldn't overlook our big, bright neighbor so much when it comes to exploring the regions beyond Earth. Our only natural satellite still has plenty of surprises in store for us.</s>The Moon may have huge reservoirs of water trapped under the surface in the form of volcanic 'glass beads', which could be extracted and used by astronauts in future lunar colonies, scientists have found.

A new study of satellite data found that numerous volcanic deposits distributed across the surface of the Moon contain unusually high amounts of trapped water.

The finding of water in these ancient deposits, which are believed to consist of glass beads formed by the explosive eruption of magma coming from the deep lunar interior, bolsters the idea that the lunar mantle is surprisingly water-rich.

Scientists had assumed for years that the interior of the Moon had been largely depleted of water and other volatile compounds.

In 2008, researchers detected trace amounts of water in some of the volcanic glass beads brought back to Earth from the Apollo 15 and 17 missions to the Moon.

In 2011, further study of tiny crystalline formations within those beads revealed that they actually contain similar amounts of water as some basalts on Earth, suggesting that the Moon's mantle contains as much water as Earth's.

"The key question is whether those Apollo samples represent the bulk conditions of the lunar interior or instead represent unusual or perhaps anomalous water-rich regions within an otherwise 'dry' mantle," said Ralph Milliken, an associate professor at Brown University in the US.

"By looking at the orbital data, we can examine the large pyroclastic deposits on the Moon that were never sampled by the Apollo or Luna missions," said Milliken.

"The fact that nearly all of them exhibit signatures of water suggests that the Apollo samples are not anomalous, so it may be that the bulk interior of the Moon is wet," he said.

Scientists used orbital spectrometers to measure the light that bounces off a planetary surface.

By looking at which wavelengths of light are absorbed or reflected by the surface, scientists can get an idea of which minerals and other compounds are present.

Researchers looked at data from the Moon Mineralogy Mapper, an imaging spectrometer that flew aboard India's Chandrayaan-1 lunar orbiter.

They found evidence of water in nearly all of the large pyroclastic deposits that had been previously mapped across the Moon's surface, including deposits near the Apollo 15 and 17 landing sites where water-bearing glass bead samples were collected.

Water-rich deposits are spread across the lunar surface, which tells us that the water found in the Apollo samples is not a one-off, Milliken said.

The idea that the interior of the Moon is water-rich could have implications for future lunar exploration.

The volcanic beads do not contain a lot of water - about 0.05 per cent by weight - but the deposits are large, and the water could potentially be extracted, researchers said.

"Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative," said Shuai Li, a postdoctoral researcher at the University of Hawaii in the US.</s>Ancient volcanic deposits on the moon suggest the lunar interior has a substantial amount of water.

Ancient volcanic deposits on the moon reveal new evidence about the lunar interior, suggesting it contains substantial amounts of water.

Using satellite data, scientists from Brown University studied lunar pyroclastic deposits, layers of rock that likely formed from large volcanic eruptions. The magma associated with these explosive events is carried to the moon's surface from very deep within its interior, according to a study published today (July 24) in Nature Geoscience.

Previous studies have observed traces of water ice in shadowed regions at the lunar poles. However, this water is likely the result of hydrogen that comes from solar wind, according to the new study's lead author, Ralph Milliken, a geologist at Brown University. The new research reveals there is likely a large amount of water in the moon's mantle, as well. This suggests that the water was delivered to the moon very early in its formation, before it fully solidified, Milliken told Space.com. [Photos: The Search for Water on the Moon]</s>Living on the Moon may be easier than first thought, after scientists discovered large amounts of water trapped beneath the surface.

It was generally assumed that the Moon was a fairly dry lump of rock, although ice still exists at the poles.

Both Nasa and the European Space Agency are keen to establish a lunar base to act as a stepping stone for the rest of the Solar System, and have been looking into whether water could be mined.

Researchers at Brown University in the US began to suspect there might be more water than previously thought after reexamining volcanic glass beads brought back by the Apollo 15 and 17 missions.

They discovered that the beads contain similar amounts of water as basalt rocks on Earth, suggesting that parts of the Moon’s crust contain as much water as our own planet.</s>Parts of the Moon’s mantle – the layer between crust and outer core – could contain as much water as Earth’s interior, says new research that uses light data to measure the mineral makeup of the lunar surface.

Researchers Ralph E. Milliken and Shuai Li at Brown University, USA have used light data to measure the makeup of volcanic deposits scattered across the lunar surface, and found a surprising amount of water.

Their study, published this week in Nature Geoscience, contributes to mounting evidence that the Moon’s interior is far more water-rich than previously thought.

Serious discussions of lunar water arose in 2008, when volcanic glass beads brought back to Earth by Apollo missions were found to contain traces of water. Since then, there’s been a question mark over whether this might be a common occurrence, or more of an anomaly.

To investigate this, Milliken and Li measured light reflected off the Moon’s surface across its orbit, using different wavelengths to estimate which compounds are present in a particular area.

They combined this data with existing mapping of large pyroclastic deposits – remnants of magma eruptions from deep within the Moon’s interior – that lie dormant across the surface.

“By looking at the orbital data, we can examine the large pyroclastic deposits on the Moon that were never sampled by the Apollo or Luna missions,” writes Milliken, lead author of the study.

“The fact that nearly all of them exhibit signatures of water suggests that the Apollo samples are not anomalous, so it may be that the bulk interior of the Moon is wet.”

The far-reaching range of these deposits, Milliken says, is crucial. “They’re spread across the surface, which tells us that the water found in the Apollo samples isn't a one-off. Lunar pyroclastics seem to be universally water-rich, which suggests the same may be true of the mantle."

The team says the presence of water on the Moon’s surface could be useful for future explorations, because it could potentially be extracted and used to nourish astronauts.

“Other studies have suggested the presence of water ice in shadowed regions at the lunar poles, but the pyroclastic deposits are at locations that may be easier to access,” explains co-author, Shuai Li.

“Anything that helps save future lunar explorers from having to bring lots of water from home is a big step forward, and our results suggest a new alternative.”
Brown University researchers discover that a substantial amount of water may be present beneath the surface of the Moon.