In January 2019, China landed its Chang’e 4 mission on the Moon’s far side. The Yutu-2 rover got busy exploring its surroundings. It’s still going, even though the rover’s nominal operating mission was only three months.
Among the mission’s findings was a strange material described as “gel-like.” Now an analysis of the material has revealed that it’s just rock: impact melt breccia.
Long before the Apollo missions reached the Moon, Earth’s only satellites has been the focal point of intense interest and research. But thanks to the samples of lunar rock that were returned to Earth by the Apollo astronauts, scientists have been able to conduct numerous studies to learn more about the Moon’s formation and history. A key research goal has been determining how much volatile elements the Moon possesses.
Intrinsic to this is determining how much water the Moon possesses, and whether it has a “wet” interior. If the Moon does have abundant sources of water, it will make establishing outposts there someday much more feasible. However, according to a new study by an international team of researchers, the interior of the Moon is likely very dry, which they concluded after studying a series of “rusty” lunar rock samples collected by the Apollo 16 mission.
Determining how rich the Moon is in terms of volatile elements and compounds – such as zinc, potassium, chlorine, and water – is important because it provides insight into how the Moon and Earth formed and evolved. The most-widely accepted theory is that Moon is the result of “catastrophic formation”, where a Mars-sized object (named Theia) collided with Earth about 4.5 billion years ago.
The debris kicked up by this impact eventually coalesced to form the Moon, which then moved away from Earth to assume its current orbit. In accordance with this theory, the Moon’s surface would have been an ocean of magma during its early history. As a result, volatile elements and compounds within the Moon’s mantle would have been depleted, much in the same way that the Earth’s upper mantle is depleted of these elements.
“It’s been a big question whether the moon is wet or dry. It might seem like a trivial thing, but this is actually quite important. If the moon is dry – like we’ve thought for about the last 45 years, since the Apollo missions – it would be consistent with the formation of the Moon in some sort of cataclysmic impact event that formed it.”
For the sake of their study, the team examined a lunar rock named “Rusty Rock 66095” to determine the volatile content of the Moon’s interior. These rocks have mystified scientists since they were first brought back by the Apollo 16 mission in 1972. Water is an essential ingredient to rust, which led scientists to conclude that the Moon must have an indigenous source of water – something which seemed unlikely, given the Moon’s extremely tenuous atmosphere.
Using a new chemical analysis, Day and his colleagues determined the levels of istopically light zinc (Zn66) and heavy chlorine (Cl37), as well as the levels of heavy metals (uranium and lead) in the rock. Zinc was the key element here, since it is a volatile element that would have behaved somewhat like water under the extremely hot conditions that were present during the Moon’s formation.
Ultimately, the supply of volatiles and heavy metals in the sample support the theory that volatile enrichment of the lunar surface occurred as a result of vapor condensation. In other words, when the Moon’s surface was still an ocean of hot magma, its volatiles evaporated and escaped from the interior. Some of these then condensed and were deposited back on the surface as it cooled and solidified.
This would explain the volatile-rich nature of some rocks on the lunar surface, as well as the levels of light zinc in both the Rusty Rock samples and the previously-studied volcanic glass beads. Basically, both were enriched by water and other volatiles thanks to extreme outgassing from the Moon’s interior. However, these same conditions meant that most of the water in the Moon’s mantle would have evaporated and been lost to space.
This represents something of a paradox, in that it shows how rocks that contain water were formed in a very dry, interior part of the Moon. However, as Day indicated, it offers a sound explanation for an enduring lunar mystery:
“I think the Rusty Rock was seen for a long time as kind of this weird curiosity, but in reality, it’s telling us something very important about the interior of the moon. These rocks are the gifts that keep on giving because every time you use a new technique, these old rocks that were collected by Buzz Aldrin, Neil Armstrong, Charlie Duke, John Young, and the Apollo astronaut pioneers, you get these wonderful insights.”
These results contradict other studies that suggest the Moon’s interior is wet, one of which was recently conducted by researchers at Brown University. By combining data provided by Chandrayaan-1 and the Lunar Reconnaissance Orbiter (LRO) with new thermal profiles, the Brown research team concluded that lots of water exists within volcanic deposits on the Moon’s surface, which could also mean there are vast quantities of water in the Moon’s interior.
To these, Day emphasized that while these studies present evidence that water exists on the lunar surface, they have yet to offer a solid explanation for what mechanisms deposited it on the surface. Day and his colleague’s study also flies in the face of other recent studies, which claim that the Moon’s water came from an external source – either by comets which deposited it, or from Earth during the formation of the Earth-Moon system.
Those who believe that lunar water was deposited by comets cite the similarities between the ratios of hydrogen to deuterium (aka. “heavy hydrogen”) in both the Apollo lunar rock samples and known comets. Those who believe the Moon’s water came from Earth, on the other hand, point to the similarity between water isotopes on both the Moon and Earth.
In the end, future research is needed to confirm where all of the Moon’s water came from, and whether or not it exists within the Moon’s interior. Towards this end, one of Day’s PhD students – Carrie McIntosh – is conducting her own research into the lunar glass beads and the composition of the deposits. These and other research studies ought to settle the debate soon enough!
And not a moment too soon, considering that multiple space agencies hope to build a lunar outpost in the upcoming decades. If they hope to have a steady supply of water for creating hydrazene (rocket fuel) and growing plants, they’ll need to know if and where it can be found!
Ever since we began sending crewed missions to the Moon, people have been dreaming of the day when we might one day colonize it. Just imagine, a settlement on the lunar surface, where everyone constantly feels only about 15% as heavy as they do here on Earth. And in their spare time, the colonists get to do all kinds of cool research trek across the surface in lunar rovers. Gotta admit, it sounds fun!
More recently, the idea of prospecting and mining on the Moon has been proposed. This is due in part to renewed space exploration, but also the rise of private aerospace companies and the NewSpace industry. With missions to the Moon schedules for the coming years and decades, it seems logical to thinking about how we might set up mining and other industries there as well?
Several proposals have been made to establish mining operations on the Moon; initially by space agencies like NASA, but more recently by private interests. Many of the earliest proposals took place during the 1950s, in response to the Space Race, which saw a lunar colony as a logical outcome of lunar exploration.
For instance, in 1954 Arthur C. Clarke proposed a lunar base where inflatable modules were covered in lunar dust for insulation and communications were provided by a inflatable radio mast. And in 1959, John S. Rinehart – the director of the Mining Research Laboratory at the Colorado School of Mines – proposed a tubular base that would “float” across the surface.
Since that time, NASA, the US Army and Air Force, and other space agencies have issued proposals for the creation of a lunar settlement. In all cases, these plans contained allowances for resource utilization to make the base as self-sufficient as possible. However, these plans predated the Apollo program, and were largely abandoned after its conclusion. It has only been in the past few decades that detailed proposals have once again been made.
For instance, during the Bush Administration (2001-2009), NASA entrtained the possibility of creating a “lunar outpost”. Consistent with their Vision for Space Exploration (2004), the plan called for the construction of a base on the Moon between 2019 and 2024. One of the key aspects of this plan was the use of ISRU techniques to produce oxygen from the surrounding regolith.
These plans were cancelled by the Obama administration and replaced with a plan for a Mars Direct mission (known as NASA’s “Journey to Mars“). However, during a workshop in 2014, representatives from NASA met with Harvard geneticist George Church, Peter Diamandis from the X Prize Foundation and other experts to discuss low-cost options for returning to the Moon.
The workshop papers, which were published in a special issue of New Space, describe how a settlement could be built on the Moon by 2022 for just $10 billion USD. According to their papers, a low-cost base would be possible thanks to the development of the space launch business, the emergence of the NewSpace industry, 3D printing, autonomous robots, and other recently-developed technologies.
In 2010, NASA established the Robotic Mining Competition, an annual incentive-based competition where university students design and build robots to navigate a simulated Martian environment. One of the most-important aspects of the competition is creating robots that can rely on ISRU to turn local resources into usable materials. The applications produced are also likely to be of use during future lunar missions.
And the NewSpace industry has also been producing some interesting proposals of late. In 2010, a group of Silicon Valley entrepreneurs came together for create Moon Express, a private company that plans to offer commercial lunar robotic transportation and data services, as well as the a long-term goal of mining the Moon. In December of 2015, they became the first company competing for the Lunar X Prize to build and test a robotic lander – the MX-1.
In 2010, Arkyd Astronautics (renamed Planetary Resources in 2012) was launched for the purpose of developing and deploying technologies for asteroid mining. In 2013, Deep Space Industries was formed with the same purpose in mind. Though these companies are focused predominantly on asteroids, the appeal is much the same as lunar mining – which is expanding humanity’s resource base beyond Earth.
Based on the study of lunar rocks, which were brought back by the Apollo missions, scientists have learned that the lunar surface is rich in minerals. Their overall composition depends on whether the rocks came from lunar maria (large, dark, basaltic plains formed from lunar eruptions) or the lunar highlands.
Rocks obtained from lunar maria showed large traces of metals, with 14.9% alumina (Al²O³), 11.8% calcium oxide (lime), 14.1% iron oxide, 9.2% magnesia (MgO), 3.9% titanium dioxide (TiO²) and 0.6% sodium oxide (Na²O). Those obtained from the lunar highlands are similar in composition, with 24.0% alumina, 15.9% lime, 5.9% iron oxide, 7.5% magnesia, and 0.6% titanium dioxide and sodium oxide.
These same studies have shown that lunar rocks contain large amounts of oxygen, predominantly in the form of oxidized minerals. Experiments have been conducted that have shown how this oxygen could be extracted to provide astronauts with breathable air, and could be used to make water and even rocket fuel.
The Moon also has concentrations of Rare Earth Metals (REM), which are attractive for two reasons. On the one hand, REMs are becoming increasingly important to the global economy, since they are used widely in electronic devices. On the other hand, 90% of current reserves of REMs are controlled by China; so having a steady access to an outside source is viewed by some as a national security matter.
Similarly, the Moon has significant amounts of water contained within its lunar regolith and in the permanently shadowed areas in its north and southern polar regions.This water would also be valuable as a source of rocket fuel, not to mention drinking water for astronauts.
But since that time, multiple missions have not only found samples of water on the lunar surface, but revealed evidence of where it came from. The first was India’s Chandrayaan-1 mission, which sent an impactor to the lunar surface on Nov. 18th, 2008. During its 25-minute descent, the impact probe’s Chandra’s Altitudinal Composition Explorer (CHACE) found evidence of water in the Moon’s thin atmosphere.
In November 2009, the NASA LCROSS space probe made similar finds around the southern polar region, as an impactor it sent to the surface kicked up material shown to contain crystalline water. In 2012, surveys conducted by the Lunar Reconnaissance Orbiter (LRO) revealed that ice makes up to 22% of the material on the floor of the Shakleton crater (located in the southern polar region).
But perhaps the most valuable commodity on the surface of the Moon might be helium-3. Helium-3 is an atom emitted by the Sun in huge amounts, and is a byproduct of the fusion reactions that take place inside. Although there is little demand for helium-3 today, physicists think they’ll serve as the ideal fuel for fusion reactors.
The Sun’s solar wind carries the helium-3 away from the Sun and out into space – eventually out of the Solar System entirely. But the helium-3 particles can crash into objects that get in their way, like the Moon. Scientists haven’t been able to find any sources of helium-3 here on Earth, but it seems to be on the Moon in huge quantities.
From a commercial and scientific point of view, there are several reasons why Moon mining would be beneficial to humanity. For starters, it would be absolutely essential to any plans to build a settlement on the Moon, as in-situ resource utilization (ISRU) would be far more cost effective than transporting materials from Earth.
Also, it is predicted that the proposed space exploration efforts for the 21st century will require large amounts of materiel. That which is mined on the Moon would be launched into space at a fraction of the cost of what is mined here on Earth, due to the Moon’s much lower gravity and escape velocity.
In addition, the Moon has an abundance of raw materials that humanity relies on. Much like Earth, it is composed of silicate rocks and metals that are differentiated between a geochemically distinct layers. These consist of is iron-rich inner core, and iron-rich fluid outer core, a partially molten boundary layer, and a solid mantle and crust.
In addition, it has been recognized for some time that a lunar base – which would include resource operations – would be a boon for missions farther into the Solar System. For missions heading to Mars in the coming decades, the outer Solar System, or even Venus and Mercury, the ability to be resupplied from an lunar outpost would cut the cost of individual missions drastically.
Naturally, the prospect of setting up mining interests on the Moon also presents some serious challenges. For instance, any base on the Moon would need to be protected from surface temperatures, which range from very low to high – 100 K (-173.15 °C;-279.67 °F) to 390 K (116.85 °C; 242.33 °F) – at the equator and average 150 K (-123.15 °C;-189.67 °F) in the polar regions.
Radiation exposure is also an issue. Due to the extremely thin atmosphere and lack of a magnetic field, the lunar surface experiences half as much radiation as an object in interplanetary space. This means that astronauts and/or lunar workers would at a high risk of exposure to cosmic rays, protons from solar wind, and the radiation caused by solar flares.
Then there’s the Moon dust, which is an extremely abrasive glassy substance that has been formed by billions of years of micrometeorite impacts on the surface. Due to the absence of weathering and erosion, Moon dust is unrounded and can play havoc with machinery, and poses a health hazard. Worst of all, its sticks to everything it touches, and was a major nuisance for the Apollo crews!
And while the lower gravity is attractive as far as launches are concerned, it is unclear what the long-term health effects of it will be on humans. As repeated research has shown, exposure to zero-gravity over month-long periods causes muscular degeneration and loss of bone density, as well as diminished organ function and a depressed immune system.
And while there has been plenty of speculation about a “loophole” which does not expressly forbid private ownership, there is no legal consensus on this. As such, as lunar prospecting and mining become more of a possibility, a legal framework will have to be worked out that ensures everything is on the up and up.
Though it might be a long way off, it is not unreasonable to think that someday, we could be mining the Moon. And with its rich supplies of metals (which includes REMs) becoming part of our economy, we could be looking at a future characterized by post-scarcity!
Alarmingly, some of our Moon rocks are missing! After the Apollo Moon landings, then-U.S. President Richard Nixon distributed approximately 250 displays containing lunar surface materials from Apollo 11 (1969) to the 50 states and various other countries around the world, and then later gave away 135 rock samples from Apollo 17 (1972). But NASA is finding that a surprisingly low percentage of these precious rock samples — which are encased in acrylic and mounted on a plaque along with the intended recipient’s flag — can actually be located.
Earlier this week, an article in the Honolulu Advertiser rejoiced that Hawaii’s missing Moon rocks had been found in a locked cabinet. The rocks weren’t technically lost, an advisor to Hawaii’s governor said, they just didn’t know exactly where they were.
That seems to be the case with many other Moon rock samples. When the rocks were given away 40 years ago, they became the property of the countries or states who received them. As time passed, administrations or regimes changed, and the rocks were likely either lost, stolen or locked away who knows where.
Joseph Gutheinz, a professor with the University of Phoenix who teaches investigative techniques now has 28 students hunting down the missing moon rocks around the nation and the world.
I was happy to see the two Moon rock samples given to the state of Illinois – where I currently live—are safe and sound. And in response to the search by one of Gutheinz’s students, Lisa Moore, the Illinois State Museum decided to put the Moon rocks back on display, after a ten-year hiatus.
“The Moon rocks given to the State of Illinois haven’t been on display for about 10 years, at least in our permanent display,” said Chris Widga, Assistant Curator of Geology at the Illinois State Museum. “But when they are not on display they are at the Research and Collections Center that we have here in Springfield, or they do make it out one to three times a year to various rock, gem and mineral shows. So they usually get seen by quite a few people.”
But now they’ll be viewed by many more eyes, as they are in the lobby of the museum.
The sample from Apollo 11 is a Lucite ball with a four small rocks (more like pebble-sized) and the rock from Apollo 17 is one larger, about the size of a dime.
I asked Widga if beyond possibly picking up some SWAG at rock and mineral conventions, if the Illinois Moon rocks have had any other excitement such as going to an interesting location or being viewed by a celebrity.
“You know, I don’t think so,” he said. “They lead a fairly dull and boring life, which is probably good given some of their cousins have been lost. If we ever have a difficult time locating objects in our collection they usually are ones described as being from 1855 or something like that, further back in time and more difficult to track down.”
But I also found out there are two other Moon rock samples in Illinois that I wasn’t aware of. However, they are likely not Apollo Moon rocks, but perhaps meteorites, that may be from the Moon.
The Funk Prairie Home & Rock Museum in Shirley, Illinois has what they say are two Moon rock samples. They are part of the collection of Lafayette Funk, a member of the family who founded the Funk Seed Company.
“As far as we can tell, Mr. Funk got them from President Nixon,” said Bill Case, curator of the Funk Museum. “He was presented with them at a conference, and on the case it says, ‘Tektite from the Moon, established from the Third International Tektite Symposium, co-sponsored by the Smithsonian Institute and the Corning Museum of Glass’.”
Case said the rocks are in glass cases, and are pock-marked black tektite; one is tear-dropped shaped and about 3.5 inches long by 1.25 inches wide, and a half an inch thick. The other is more rounded, about 2 inches across, and one edge is chipped off to show the shiny, glassy black interior.
“Mr. Funk built a mineral museum, and he collected minerals from all over the world,” Case said. “He had wide-ranging contacts from all over the world and the Funks were advisers to various presidents, so it is not surprising that he would receive something from the President of the United States. In fact we have cases of things from various heads of states.”
Case said recently, a friend of Lafayette Funk who was on board the aircraft carrier with President Nixon when Apollo 11 splashed down gave the museum a photograph and confirmed that the time period when Lafayette got the Moon rocks was during the Apollo missions.
According to Robert Pearlman of CollectSPACE, however, no individual was ever presented with an Apollo-recovered moon rock, not even a president, astronaut, religious figure or state leader. “The only moon rocks returned by astronauts ever given away were those presented as goodwill gifts to the citizens of the nations/states as listed within the two guides on collectSPACE,” Pearlman told Universe Today. “Tektites are not confirmed to be of lunar origin. They were believed to be from the Moon but other research suggests they are terrestrial material that was ejected back into space (by impact or volcanic eruption) and then reentered through the atmosphere.”
So, these rocks may or may not be from the Moon. If any readers have any insight on these rocks, we’d love to hear about it.
Unfortunately, some of the diplomatic gifts of Apollo lunar samples have found their way onto the black market. There’s no real way to know exactly how valuable the Moon rocks are, said Pearlman, because there are so few samples to judge the market. But Gutheinz believes they could be worth up to $10 million each.
Each Apollo mission brought back between 60 and 110 kg of lunar materials and the majority of Moon rocks are housed in the Lunar Receiving Laboratory at Johnson Space Center.
NASA’s education program loans out lunar samples to specially certified educator to use, and the restrictions for storing and using the educational samples are quite strict. It is regrettable that the diplomatic lunar samples didn’t have equal care and and restrictions.
In May of last year, we followed the story of former astronaut Scott Parazynski, as he climbed Mt. Everest to collect a piece of the mountain and test out equipment for NASA. During the climb, Parazynski carried a Moon rock that was brought to the Earth by the Apollo 11 mission. Though the journey of this rock has been rather long, it is about to come to an end.
The rock, along with a piece of Mt. Everest that Parazynski collected, will travel to the International Space Station during the next Space Shuttle mission. It and the Mt. Everest rock will be displayed in the Tranquility (*cough* Colbert *cough*) module, which is part of the payload of STS-130.
Endeavour is currently scheduled to launch on February 7th, 2010 and will carry the Tranquility module, which will provide more life-support systems for the ISS, as well as a seven-windowed cupola that will be used as an observation and control room for control of the robotic arm outside the station.
Interestingly enough, the rock originated in the Sea of Tranquility on the Moon, and will be returning to be displayed inside the Tranquility module itself.
The Moon rock and piece of Mt Everest will be presented by Parazynski to STS-130 commander George Zamka this Wednesday, January 6th. You can watch the presentation on NASA TV at 3:30pm CST.