Tag Archives: Moon

Scientists finally image SMART-1 lunar impact site

SMART-1 impact site

Eleven years after the European SMART-1 probe was sent crashing onto the Moon’s surface, scientists have finally identified in a Lunar Reconnaissance Orbiter image that crash site.

The image is shown on the right, reduced and cropped to post here.

The images show a linear gouge in the surface, about four metres wide and 20 metres long, cutting across a small pre-existing crater. At the far end, a faint fan of ejecta sprays out to the south. Foing said: “The high resolution LRO images show white ejecta, about seven metres across, from the first contact. A north-south channel has then been carved out by the SMART-1 spacecraft body, before its bouncing ricochet. We can make out three faint but distinct ejecta streams from the impact, about 40 metres long and separated by 20-degree angles.”

Stooke said: “Orbit tracking and the impact flash gave a good estimate of the impact location, and very close to that point was a very unusual small feature. It now seems that impacts of orbiting spacecraft, seen here from SMART-1, and also in the cases from GRAIL and LADEE, will form elongated craters, most of whose rather faint ejecta extends downrange”.


First global map of the trace water on the Moon

Trace water on moon

Using data collected by an American instrument on India’s Chandrayaan-1 lunar orbiter scientists have produced the first global map showing the locations and quantities of trace water on the Moon.

The map above, reduced to post here, is the result. The green areas at high latitudes show the most evidence of water, but the amounts remain very tiny, and the evidence remains somewhat uncertain.

Regardless, this map indicates that the high latitudes of the Moon will likely be the most valuable real estate for future colonists.


Cell towers to the Moon!

Capitalism in space: A startup that intends to land two privately built rovers near the Apollo 17 landing site in 2018 also plans to use basic cell tower technology to relay what the rovers find back to Earth.

Part Time Scientists has a launch contract for late 2018 with Space X as a secondary payload on the Falcon 9 rocket. Becker said the company believes it will be the first private entity to reach the surface of the moon, suggesting that none of the Google Lunar X Prize participants are likely to meet the December 2017 deadline for the competition. (Part Time Scientists itself withdrew from the Google Lunar X Prize earlier this year due to the time constraints of the competition.)

The Falcon 9 will carry the team’s spacecraft, Alina, to the geostationary transfer orbit, a highly elliptical Earth orbit whose highest point is 26,000 miles (42,000 kilometers). From there, Alina will continue on its own to the moon. “We will soft-land on the moon and disembark our two rovers, the Audi Lunar Quatro rovers, with which we are going to drive up to Apollo 17,” Becker said. “The two rovers are essentially mobile phones that will communicate our video stream to Alina, which serves as an LTE base station, and Alina will communicate the data to us,” he said.

What is most significant about this is that even if no one wins the Google Lunar X-Prize this year, it appears that the contest succeeded nonetheless. At least two if not five different companies appear funded and about to launch private rovers to the Moon. Once they demonstrate this capability, they will certainly be positioned to make money offering it to nations and scientists worldwide. For example, NASA and China both want to place probes in remote places on the Moon, near the poles or on the Moon’s far side. If this mission by Part Time Scientists is a success, they will then be able to offer a cheap method for relaying communications from those locations.


The difficult task of legally preserving the Apollo lunar sites

Link here.

While I heartily agree that these historic sites should be preserved, if you read the article you will notice how the focus with these people is not the future, but preserving relics of the past. I say we don’t need more memorials. The best memorial for Apollo 11 would be thriving city on the Moon, even if it trampled on Tranquility Base.

Note also that the restrictions imposed by the Outer Space Treaty once again make things worse. Under the treaty, there is no way for the U.S. to reasonably preserve these American historical sites, without first getting the approval of the UN. The result? I guarantee that any arrangement we manage to work out will almost certainly restrict the freedoms of future space colonists. This not a good thing, and it certainly isn’t something we here on Earth should be doing to the brave people who will someday want to build new civilizations on other worlds.


Lunar landers/rovers for sale!

Moon Express, one of the five finalists trying to win the Google Lunar X-Prize (GLXP) before it expires at the end of this year, announced today its long range plans, focused on building low cost lunar landers rovers, and sample return missions that could be purchased and launched for a tenth the cost of a typical government mission.

The GLXP mission won’t be the last lunar voyage for Moon Express, if all goes according to plan. Its deal with Rocket Lab covers up to five launches, and Moon Express wants at least two more to occur in the next few years, Richards revealed during a news conference today.

The first post-GLXP mission, scheduled to launch in 2019, will set up a robotic research outpost near the lunar south pole and prospect for water and other resources. Then, in 2020, Moon Express will launch the first commercial lunar sample-return mission. That effort, Richards said, should prove out the company’s technologies and its business model, which is centered around creating low-cost access to the moon’s surface for a variety of customers. The core piece of hardware to make all of that happen is a single-engine lander called the MX-1, which will launch on the GLXP flight. Moon Express aims to mass-produce the MX-1, sell it as a stand-alone lunar explorer and have it serve as a building block for three larger, more capable spacecraft — the MX-2, the MX-5 and the MX-9, Richards said today.

The MX-2 combines two MX-1s into a single package, boosting the MX-1’s payload capacity in Earth-moon space and potentially enabling missions to Venus or the moons of Mars. As their names suggest, the MX-5 and MX-9 incorporate five engines and nine engines, respectively, and broaden the exploration envelope even further, Richards said. All of these spacecraft will be available in orbiter, lander and deep-space variations, and the MX-5 and MX-9 vehicles will also come in a sample-return configuration.

Moon Express has not revealed how much it will charge for any of these spacecraft. However, company representatives have said that, together, the MX-1 and Electron can deliver a lunar mission for less than $10 million (that’s “cost,” not retail). Electron flights currently sell for about $5.5 million apiece, putting the lander’s raw cost at $4.5 million or less.

Essentially, they are taking the revolution in satellite technology that is making everything smaller and cheaper and applying it to planetary exploration. They are then offering this technology as a very cheap and fast option for scientists and governments. Based on these numbers, a mission to the Moon could cost a customer less than $20 million, which is nothing compared to a typical NASA mission. Even India’s Mars Orbiter was several times more expensive than this.

While I consider NASA’s planetary program second to none, and one of the best things it does, Moon Express is demonstrating, as has SpaceX with launch services, that private enterprise, if given the chance, can do it better.


China begins 200-day simulated self-sufficient space station experiment

The new colonial movement: Four Chinese students yesterday began a 200 day experiment, living in a simulated ground-based space station that will attempt to be self-sufficient for the entire time.

The underlying but unstated goal is revealed by this quote:

But the 200-day group will also be tested to see how they react to living a for period of time without sunlight. The project’s team declined to elaborate. “We did this experiment with animals… so we want to see how much impact it will have on people,” Liu, the professor, said.

They aren’t just testing the self-sufficiency of a future interplanetary spaceship. They are also testing the self-sufficiency of a lunar base, which must undergo 14 days of darkness each lunar day. I wonder if the facility is also subjected to no sunlight during these tests.


JAXA proposes Japan send humans to the Moon

The new colonial movement: Japan’s space agency JAXA has proposed that Japan participate in a lunar manned mission to be flown by the 2030s.

The report is very vague. It suggests that Japan create such a mission, but also do it as part of a larger international effort, which presently doesn’t even exist.


China to attempt to grow potatoes on Moon

China’s Chang’e-4 lunar rover/lander, set to launch in 2018, will include a small experiment that will attempt to grow potatoes from seeds.

Note that I have just realized that I have been confusing Chang’e-5 with Chang’e-4. Chang’e-5 is a sample return mission that they hope to launch this year. It does not include a rover. Chang’e-4 is a lander/rover mission that is planned for 2018.


China reveals landing site for Chang’e-5 lander/rover

China has chosen the landing site for its Chang’e-5 lander/rover and sample return mission, planned to launch later this year.

Liu Jizhong, director of China Lunar Exploration and Space Engineering Center of China National Space Administration (CNSA), for the first time disclosed the probe landing site, an isolated volcanic formation located in the northwest part of the Moon’s near side.

They also said their focus will be the Moon’s south pole, where there is evidence of the possible presence of water ice.


Frost on the Moon?

A new analysis of Lunar Reconnaissance Orbiter data suggests that the coldest spots at the Moon’s south pole are also its brightest, even though they are generally in shadow, suggesting that the surface there might have a thin layer of water frost.

These are also the areas where hydrogen has been detected, which strengthens the theory that this is water.

However, the result is not a positive one for future colonists as it suggests that the amount of water on the Moon is far less than hoped. First, there is this:

The icy deposits appear to be patchy and thin, and it’s possible that they are mixed in with the surface layer of soil, dust and small rocks called the regolith. The researchers say they are not seeing expanses of ice similar to a frozen pond or skating rink. Instead, they are seeing signs of surface frost.

Second, they have not detected this same pattern at the north pole, which strongly suggests that the permanently shadowed areas there do not even have frost.

Overall, this result suggests that the Moon might have water on its surface, but not in great quantities.


LRO hit by meteoriod in 2014

LRO as it was hit by a meteor

While taking an image in October 2014, Lunar Reconnaissance Orbiter had apparently been hit by some small object, causing it to vibrate and create the zig-zag distortions seen on the image, a cropped section of which is shown on the right.

Clearly there was a brief violent movement of the left NAC [Narrow Angle Camera]. The only logical explanation is that the NAC was hit by a meteoroid! How big was the meteoroid, and where did it hit? The physical properties and vibration modes of the NAC are very well known – during development a detailed computer model was made to ensure the NAC would not fail during the vibrations caused by the launch, which are severe. The computer model was tested before launch by attaching the NAC to a vibration table that simulates launch. The model was solid, both NACs survived the test, and launch.

Most of each NAC is sequestered inside the spacecraft structure, so only the leading edge of the baffle and the radiator are exposed to space, and thus are potential targets for impactors. From the detailed computer model, the LROC team ran simulations to see if we could reproduce the distortions seen the image. Assuming an impact velocity of 7 kilometers per second and a density 2.7 g/cm3, an impacting particle would have been 0.8 mm in diameter (~half the size of a pinhead). If the velocity was faster, then the particle would have been smaller, and if slower then larger.

For comparison, the muzzle velocity of a bullet fired from a rifle is typically 0.5 to 1.0 kilometers per second. So the meteoroid was traveling much faster than a speeding bullet. In this case LROC did not dodge a speeding bullet, but rather survived a speeding bullet!

The image is fascinating because you can see the vibrations slowly disappear as the zig-zags shrink and fade.


3D printing of bricks, using moondust

European engineers have managed to print bricks using simulated moondust and focused sunlight.

The resulting bricks have the equivalent strength of gypsum, and are set to undergo detailed mechanical testing. Some bricks show some warping at the edges, Advenit adds, because their edges cool faster than the centre: “We’re looking how to manage this effect, perhaps by occasionally accelerating the printing speed so that less heat accumulates within the brick. But for now this project is a proof of concept, showing that such a lunar construction method is indeed feasible.”

The video at the link is very unconvincing. While it shows film of the printing process, it does not show film of anyone holding or manipulating the finished bricks. Instead, it shows one or two photos of finished bricks, all of which give the impression that these bricks crumble easily at the edges, I suspect that the bricks are simply too fragile for practical use.

So, is this a proof of concept? Maybe. They have at least shown that 3D printing using materials on the Moon might work.


NASA looks to private companies for lunar missions

Capitalism in space: NASA has issued a request for information on possible private commercial missions capable of carrying NASA payloads to the Moon.

From the announcement:

NASA has identified a variety of exploration, science, and technology demonstration objectives that could be addressed by sending instruments, experiments, or other payloads to the lunar surface. To address these objectives as cost-effectively as possible, NASA may procure payloads and related commercial payload delivery services to the Moon

In other words, NASA has money to spend on lunar science missions, and rather than plan those missions itself, as it has done since the 1960s, it is now offering to buy and launch proposals from private companies.


Court allows lawsuit against NASA agent who detained elderly couple

A court has ruled that an elderly couple can sue NASA and the agent that detained them for possessing a tiny Moon rock that had been given to the woman’s deceased previous husband for his work at NASA in the 1960s.

The U.S. 9th Circuit Court of Appeals said Joann Davis, the widow of an engineer who worked with NASA, was entitled to show that her detention was “unreasonably prolonged and unnecessarily degrading.”

The federal agent “organized a sting operation involving six armed officers to forcibly seize a Lucite paperweight containing a moon rock the size of a rice grain from an elderly grandmother,” Chief 9th Circuit Judge Sidney R. Thomas wrote for a three-judge panel.

Read the whole story. It is another example of NASA overreach in its false believe that owns all moon rocks from the Apollo missions, even those that had been given away during that time. I hope this woman bankrupts the agent for what he did. I also hope she sues NASA as well, as their policy is wrong.


Sweden delivers science instrument for Chinese lunar probe

The new colonial movement: The Swedish Institute of Physics has completed construction and delivered a science instrument to be flown on China’s Chang’e 4 spacecraft that will bring an orbiter, lander, and rover to the Moon’s far side in 2018.

The instrument will be installed on the rover, and will study the surface and how it interacts with the solar wind. This will also be a continuation of research performed by India’s Chandayaan-1 orbiter.


Blue Origin proposes unmanned lunar mission

The competition heats up: Blue Origin has proposed building for NASA an unmanned lunar mission to visit Shackleton Crater at the Moon’s south pole by 2020.

The Post says the company’s seven-page proposal, dated Jan. 4, has been circulating among NASA’s leadership and President Donald Trump’s transition team. It’s only one of several proposals aimed at turning the focus of exploration beyond Earth orbit to the moon and its environs during Trump’s term.

As described by the Post, the proposal seeks NASA’s support for sending a “Blue Moon” lander to Shackleton Crater near the moon’s south pole. The lander would be designed to carry up to 10,000 pounds of payload. It could be launched by Blue Origin’s New Glenn rocket, which is currently under development, or by other vehicles including NASA’s Space Launch System or United Launch Alliance’s Atlas 5. [emphasis mine]

The important take-away from this story is not the proposal to go to the Moon, but the proposal, as highlighted, that other rockets could do it instead of SLS. Though the proposal includes SLS as a possible launch vehicle, NASA’s giant rocket simply won’t be ready by 2020. That New Glenn might be illustrates again how much better private space does things, as this rocket is only now beginning development. If it is ready by 2020, which is what Blue Origin has been promising, it will have taken the company only about four years to build it, one fourth the time it is taking NASA to build SLS.


Bigelow advocates his space stations for lunar missions

The competition heats up: Robert Bigelow today advocated using his privately built inflatable space station modules as a tool for launching future American lunar missions.

Bigelow’s company is eager to put a space station depot in lunar orbit, from which such activities and others can be initiated, as well as support onboard research. “We do not have the technologies, and there is zero business case for Mars. We do have a business case for the moon. And that’s why the moon absolutely makes the best sense,” Bigelow said. “And we can do the lunar activities far sooner than we can with Mars, which stretches out to, NASA’s views are Mars may be in the 2040s.”

His “New Space” company, Bigelow Aerospace of Las Vegas, designs space habitats, including a fully self-contained space station with 330 cubic meters of living and working space, which he said is ready for a lower-Earth orbit or, in about three years given the expected advancements in rocketry, for lunar orbit.

The key statement above is the comparison between lunar missions and Mars missions, at this time. The Moon has the chance to be profitable in the near future. Mars does not. If you had money to invest (even if it is taxpayer dollars) which would you invest it in?


NASA considers putting astronauts on first SLS/Orion flight

Faced with indications that Trump wants a manned lunar mission during his first term, NASA’s acting administrator has asked his engineers and management to look into the possibility of putting humans on the first SLS/Orion launch, now set for late in 2018.

As the Acting Administrator, my perspective is that we are on the verge of even greater discoveries. President Trump said in his inaugural address that we will “unlock the mysteries of space.” Accordingly, it is imperative to the mission of this agency that we are successful in safely and effectively executing both the SLS and Orion programs.

Related to that, I have asked Bill Gerstenmaier to initiate a study to assess the feasibility of adding a crew to Exploration Mission-1, the first integrated flight of SLS and Orion. I know the challenges associated with such a proposition, like reviewing the technical feasibility, additional resources needed, and clearly the extra work would require a different launch date. That said, I also want to hear about the opportunities it could present to accelerate the effort of the first crewed flight and what it would take to accomplish that first step of pushing humans farther into space. The SLS and ORION missions, coupled with those promised from record levels of private investment in space, will help put NASA and America in a position to unlock those mysteries and to ensure this nation’s world pre-eminence in exploring the cosmos.

This is incredibly stupid. That first flight will be the very first time SLS will fly. It will also be flying with an upper stage engine that has also never flown before. It will take the Orion capsule to the Moon, when the capsule itself has not yet even done one orbit around the Earth. To put people on it makes no engineering sense at all.


Gene Cernan, 82, has passed away

Gene Cernan, the last Apollo astronaut to walk on the Moon, passed away today.

His words as he stepped off the lunar surface still resonate to me.

This is Gene, and I’m on the surface; and, as I take man’s last step from the surface, back home for some time to come – but we believe not too long into the future – I’d like to just (say) what I believe history will record: that America’s challenge of today has forged man’s destiny of tomorrow. And, as we leave the Moon at Taurus–Littrow, we leave as we came and, God willing, as we shall return, with peace and hope for all mankind. Godspeed the crew of Apollo 17.

At the time, I firmly believed that we would return relatively soon. It has now been almost a half century, and no human since has left Earth orbit.


Moon Express completes funding for Google X-Prize lunar mission

The competition heats up: Moon Express, one of the five remaining contestants vying for the Google Lunar X-Prize, announced today that it has raised an additional $20 million to complete the necessary funding needed to complete its mission.

The new round brings the total Moon Express has raised to $45 million. Richards said the company is looking to raise an additional $10 million as a “contingency” and to support future missions. “This is not a stunt,” he said. “We’re not putting all our eggs in one basket.”

The company is developing a small lunar lander called the MX-1E. The spacecraft is designed to land on the moon and then “hop” to another landing site, fulfilling the requirement of the Google Lunar X Prize to travel at least 500 meters across the surface after landing. That initial mission will carry scientific and commercial payloads from several customers. Richards said Moon Express is currently focusing on the spacecraft’s key technology, its propulsion system. The company previously tested that propulsion technology in tests at NASA’s Kennedy Space Center, but Richards said the company is making changes to improve its performance.

That additional performance is needed since the spacecraft will launch on Electron, a small launch vehicle being developed by U.S.-New Zealand company Rocket Lab, which can only take the lander into low Earth orbit. Earlier mission concepts called for launching on a larger vehicle that could place the spacecraft into a geostationary transfer orbit. “We need that extra punch from our own engine in order to get to the moon,” Richards said.

The article provides one more tidbit, this time about Rocket Lab and its Electron rocket:

The company’s current schedule calls for integrating the spacecraft in July, and then shipping it to Rocket Lab’s New Zealand launch site in October. The launch, scheduled for late this year, will be the seventh or eighth operational flight of the Electron, Richards said, shortly after a NASA mission under a Venture Class Launch Services contract Rocket Lab received in late 2015.

Although Rocket Lab has yet to launch an Electron — its first test flight is scheduled for no earlier than February — Richards believed the company would be ready in time for Moon Express, which faces a deadline of the end of this year to win the $20 million Google Lunar X Prize before the prize expires. [emphasis mine]

In other words, if things go as planned, Rocket Lab will launch Electron in February, and then do about one launch per month before it launches Moon Express. That will be an impressive start for the new rocket company, should they succeed in doing it.


The Earth and Moon, as seen from Mars

The Earth and Moon as seen from Mars

Cool image time! The image above, a composite of four separate Mars Reconnaissance Orbiter pictures, was taken on November 20, 2016.

Each was separately processed prior to combining them so that the moon is bright enough to see. The moon is much darker than Earth and would barely be visible at the same brightness scale as Earth. The combined view retains the correct sizes and positions of the two bodies relative to each other.

The reddish region on Earth is Australia, with Antarctica the bright white area below that.


Trump interested in lunar manned mission?

After meeting with Donald Trump a historian now says the president-elect appears very interested in the idea of sending a man to the Moon.

All of these stories continue to be speculation, but I strongly suspect that much of it also consists of trial balloons pushed by the various supporters of SLS/Orion in their effort to give that very expensive and so-far completely unproductive boondoggle a mission it can actually achieve. Right now, SLS/Orion has no mission. It is only funded through the first manned test flight in 2021 (likely to be delayed until 2023). Since it has been a pork barrel favorite of a number of Senators and Congressmen, I would not be surprised if they are trying to convince Trump to fund it by giving it a new Kennedy-like mission.


Fifth Google Lunar X-Prize team gets launch deal

Japan’s Team Hakuto has signed a deal to partner with another Google Lunar X-Prize competitor, Team Indus, to share the cost and launch together on a Indian PSLV rocket.

Essentially, both competitors will launch together. They will then race to the Moon to see which can first achieve the X-Prize goal of landing and roving 500 meters.


Lunar lava tubes could be big

New research now suggests that the lava tubes on the Moon have the potential to be very large, much larger than found on Earth.

On Earth, such structures max out at around 30 meters across, but the gravitational data suggest that the moon’s tubes are vastly wider. Assessing the sturdiness of lava tubes under lunar gravity, planetary geophysicist Dave Blair of Purdue University in West Lafayette, Ind., and colleagues estimate that the caves could remain structurally sound up to 5 kilometers across. That’s wide enough to fit the Golden Gate Bridge, Brooklyn Bridge and London Bridge end to end.

This isn’t really news, merely a confirmation of what other scientists have been theorizing for decades. What it tells us again is that the first permanent and successful lunar colonies will almost certainly be located in such tubes, since they provide ready-made radiation shielding as well as protection from the wild swings of temperature seen on the lunar surface. In the lava tube, the temperature will likely remain quite stable, making environmental control a much simpler problem.


Fourth Google Lunar X-Prize team gets launch deal

The competition heats up: TeamIndus, based in India, has signed a contract with ISRO to launch its Google Lunar X-Prize rover as a secondary payload on a Indian PSLV rocket.

This is the fourth X-Prize team to announce a launch contract. According to the rules, the teams have until the end of the year to obtain a contract or else they are out of the competition. We should therefore expect more of these announcements in the coming weeks.


Another Google Lunar X-Prize team secures launch contract

Part Time Scientists, one of the teams competing for the Google Lunar X-Prize, has secured a launch contract through launch rideshare broker Spaceflight Inc.

Their rover will launch as a secondary payload. It is the broker’s job to secure that slot.

PTScientists plans to land its rovers in the moon’s Taurus-Littrow valley, the last place humans set foot on the lunar surface in December 1972, in the hopes of getting a closer look at how the Apollo moon buggy has survived over the past four and a half decades in the extreme temperatures and inhospitable conditions on the moon. “There is a reason we have chosen the Apollo 17 landing site,” said Karsten Becker, PTScientists electronics head, said in a call with reporters on Tuesday. “That is because the Taurus-Littrow valley is geographically very interesting — that is why it was chosen for Apollo 17 — but it is also a very-well documented site. There are many pictures where you can see that it is very flat, and that there are not that many stones laying around.”

The landing site has been chosen to be within reach of the Apollo 17 site, but not so close that it could risk damage to the NASA preservation heritage area. “We want to land 3 to 5 kilometers [2 to 4 miles] away from the [Apollo 17] landing site,” said Becker.

This team is now the fourth X-Prize team to secure a launch contract. All are hoping to launch within the next two years.


ISRO begins ground tests of its first lunar lander

The competition heats up: ISRO, India’s space agency, has begun testing the sensors its first lunar lander, Chandrayaan-2, will use to descend safely to the surface.

ISRO Satellite Centre or ISAC, which is the lead centre for the country’s second moon mission, has artificially created eight to ten craters to make the terrain resemble the lunar surface. This terrain is now the test bed for the lunar Lander’s sensors. Between Friday and Monday, a small ISRO-owned aircraft carrying equipment with the sensors flew a few times over these craters to see how well they performed.


Kaguya data released at last

Seven years after the mission ended Japan has finally released the full catalog of images and videos taken by its lunar orbiter Kaguya.

No explanation for the long delay has been provided. Overall, this is just another example of what to me appears to be a bloated, bureaucratic, and slow to move Japanese space program. Their rockets are expensive, their planetary probes have had repeated problems, and they seem to be very uninterested in stepping up their game to compete in the increasingly competitive international race to explore and settle the solar system. That it took them more than seven years to release this data is quite shameful.


The Moon gets pounded more than expected

The uncertainty of science: A close review of Lunar Reconnaissance Orbiter (LRO) images now suggests that asteroid impacts occur 33% more than previously estimated.

The research also suggests that the lunar surface gets rechurned faster than previously thought, which could force planetary scientists to adjust their solar system aging system that is based on crater counts.

The article makes the entirely false claim that this increased rate of impacts poses a threat to lunar colonies, probably in an effort by these scientists to lobby for funds for a combined lunar orbiter-lander mission. The first lunar colonies will likely be placed below ground, partly to protect them from the harsh lunar environment as well as from radiation, and partly because that will be the easiest way to build those colonies. The impacts being measured here are all relatively small, and would not threaten these underground colonies.

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