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Thread: Does anyone still believe that Apollo 11 landed on the moon after Chang'E-4

  1. #151
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    Quote Originally Posted by Lord Foul View Post
    The less dense parts are greater than the SAA and we know the hazards it poses.
    Stop evading questions.

    Provide your exposure calculations for a transit in a 8-10g/cm^2 craft, at the recorded speeds and trajectory. Factor in the offset of 10 degrees to magnetic north, applied to a 30 degree trajectory.

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    Quote Originally Posted by Lord Foul View Post
    I don't believe you. Please show me your reference. I believe the Orion mirrored the Apollo missions but I can change my mind.
    Nobody cares what you believe about this complete strawman. What Orion flight are you referring to?

    Apollo TLI
    https://www.history.nasa.gov/SP-4029..._Injection.htm

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    Quote Originally Posted by Lord Foul View Post
    I don't think you are paying attention. A direct comparison was made between the LRO and the Chang'-e's LND and they matched almost exactly and the measurements were made a day apart. The LRO confirms that the shielding effect is offset in lunar orbit by the radiation coming from the moon. The moon is almost 6 times as radioactive as the cislunar space.
    The LRO data were "converted to water and to the lunar surface" (according to your quote)--that is, they processed the original measured dose rate to reflect the shielding level at the lunar surface, rather than in low lunar orbit, and they converted their data to better match the absorptive capacity of human tissue.
    Anyway, "six times more radioactive than cis-lunar space" implies that you think cis-lunar space has a dosage rate of ~13/6 μGy/hr in water, or 10/6 μGy/hr in silicon ... call it about 2 μGy/hr = 0.2 mrad/hr. Where does that number come from?

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    Yes, you keep repeating that, but it doesn't say what you claim it says.
    1) The Chang'E-4/LRO dose rate of 13 μGy/hour is merely double the Apollo estimate of 0.6 mrad/hr.
    2) That's exactly what the Apollo radiation analysis predicted would happen at solar minimum.
    3) You're comparing the current radiation environment to the radiation environment in 1969 every time you compare the Chang'E-4 dose-rate to the Apollo dose-rate.

    Grant Hutchison
    You chided me for comparing apples to oranges and yet you insist upon comparing a 1969 estimate to a 2019 actual reading. Fine. .6mrad/hr = 6.0ugy/hr * 24hr = 144ugy =.144mgy/day. 1.369mgy/day/ .144mgy/day =9.5 times more.

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    Quote Originally Posted by Lord Foul View Post
    The less dense parts are greater than the SAA and we know the hazards it poses.
    Citation required.

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    Quote Originally Posted by grant hutchison View Post
    The LRO data were "converted to water and to the lunar surface" (according to your quote)--that is, they processed the original measured dose rate to reflect the shielding level at the lunar surface, rather than in low lunar orbit, and they converted their data to better match the absorptive capacity of human tissue.
    Anyway, "six times more radioactive than cis-lunar space" implies that you think cis-lunar space has a dosage rate of ~13/6 μGy/hr in water, or 10/6 μGy/hr in silicon ... call it about 2 μGy/hr = 0.2 mrad/hr. Where does that number come from?

    Grant Hutchison
    So you do not believe this" Measurements taken by NASA's Lunar Reconnaissance Orbiter show that the number of high energy particles streaming in from space did not tail off closer to the moon's surface, as would be expected with the body of the moon blocking half the sky.

    Rather, the cosmic rays created a secondary — and potentially more dangerous -- shower by blasting particles in the lunar soil which then become radioactive.

    "The moon is a source of radiation," said Boston University researcher Harlan Spence, the lead scientist for LRO's cosmic ray telescope. "This was a bit unexpected."

    While the moon blocks galactic cosmic rays to some extent, the hazards posed by the secondary radiation showers counter the shielding effects, Spence said at a press conference at the American Geophysical Union meeting in San Francisco this week.

    Overall, future lunar travelers face a radiation dose 30 percent to 40 percent higher than originally expected, Spence said."

  7. #157
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    I sense goal post shifting.

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    Lord Foul, your own quote shows you to be wrong. The original expectation was that the mass of the Moon would block about half of the radiation that would otherwise be received by an astronaut on or near the Moon because it blocks about half of the sky. Spence is pointing out that secondaries add back some radiation to that so it is more than originally expected, but it is not more than in cislunar space. Rather, it is less than cislunar space. Again, we went over this already. The quote from the abstract of the more technical article made that even more clear, and I thought you understood that now, and were simply ignoring it, but apparently that was expecting too much.

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." ó Abraham Lincoln

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    GCR radiation is a different matter: it is constant, isotropic, and contains many very high-energy species that cannot be shielded by currently employed
    shielding regimes.

    https://arc.aiaa.org/doi/pdf/10.2514...0much%20higher.

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    Quote Originally Posted by Van Rijn View Post
    Lord Foul, your own quote shows you to be wrong. The original expectation was that the mass of the Moon would block about half of the radiation that would otherwise be received by an astronaut on or near the Moon because it blocks about half of the sky. Spence is pointing out that secondaries add back some radiation to that so it is more than originally expected, but it is not more than in cislunar space, Rather, it is less than cislunar space.Again, we went over this already. The quote from the abstract of the more technical article made that even more clear, and I thought you understood that now, and were simply ignoring it, but apparently that was expecting too much.
    " Measurements taken by NASA's Lunar Reconnaissance Orbiter show that the number of high energy particles streaming in from space did not tail off closer to the moon's surface, as would be expected with the body of the moon blocking half the sky.

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    LF, here is the link to the technical Spence article you supplied on page 2 of this discussion:

    Quote Originally Posted by Lord Foul View Post
    FYI: Here is a second more technical article that discusses the higher than expected lunar radiation. https://agupubs.onlinelibrary.wiley....2/2013SW000995
    An excellent article, I recommend you read it, as it would clear up some of your misconceptions. And here again is a key passage from the abstract, also presented on page 2 of this discussion. Iíve bolded key points:

    Finally, we note that when considering the lunar radiation environment, although the Moon blocks approximately half of the sky, thus essentially halving the absorbed dose rate near the Moon relative to deep space, the secondary radiation created by the presence of the Moon adds back a small, but measurable, absorbed dose (~8%) that can and should be now accounted for quantitatively in radiation risk assessments at the Moon and other similar exploration targets.

    So, as I said, radiation was higher than expected, but lower than in cislunar space. Also, this is in good agreement with the 1 mr/hr cislunar figure versus the 0.6 mr/hr lunar figure discussed regarding Apollo. Now, do you finally understand where you made a mistake?

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." ó Abraham Lincoln

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    Quote Originally Posted by Lord Foul View Post
    The less dense parts are greater than the SAA and we know the hazards it poses.
    Now how much time was spent in the inner VARB? What was the radiation received?

    What is the average iss transit time across the SAA? What amount of radiation does it receive?
    Last edited by bknight; 2021-Apr-17 at 07:54 PM. Reason: Added ISS

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    Quote Originally Posted by Lord Foul View Post
    GCR radiation is a different matter: it is constant, isotropic, and contains many very high-energy species that cannot be shielded by currently employed
    shielding regimes.

    https://arc.aiaa.org/doi/pdf/10.2514...0much%20higher.
    No one is challenging this, what we challenge is your contention that the report radiation of A11 could not have been that low(<.24) since CGR are a part of the total radiation received. Now show some calculations of the various types of radiation that A11 received. Your observation is not evidence.

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    Quote Originally Posted by Lord Foul View Post
    GCR radiation is a different matter: it is constant, isotropic, and contains many very high-energy species that cannot be shielded by currently employed
    shielding regimes.
    https://arc.aiaa.org/doi/pdf/10.2514...0much%20higher.
    Your question and request evasion continues and now you cite a paper that includes the implicit word "contains". Amongst other rays within its spectrum that CAN be shielded against!

    Question: Do you understand this?

    Or maybe this excerpt can get the penny to drop:

    "What is known with certainty is that the current radiation protection schemes do not completely shield the radiation spectrum encountered from the GCRs in the cislunar region and, in some cases, actually can be counterproductive and increase the hazard. "

    Please don't repeat your claims about secondary radiation from aluminium.
    Last edited by Clanger; 2021-Apr-17 at 08:09 PM.

  16. #166
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    Quote Originally Posted by Lord Foul View Post
    GCR radiation is a different matter: it is constant, isotropic, and contains many very high-energy species that cannot be shielded by currently employed
    shielding regimes.

    https://arc.aiaa.org/doi/pdf/10.2514...0much%20higher.
    What, in your opinion, is the relevance of this statement to the current discussion? I have some suspicions on how you might be interpreting it, but I donít want to put words in your mouth.

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." ó Abraham Lincoln

    I say there is an invisible elf in my backyard. How do you prove that I am wrong?

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    Quote Originally Posted by Lord Foul View Post
    You chided me for comparing apples to oranges and yet you insist upon comparing a 1969 estimate to a 2019 actual reading. Fine. .6mrad/hr = 6.0ugy/hr * 24hr = 144ugy =.144mgy/day. 1.369mgy/day/ .144mgy/day =9.5 times more.
    Oh, I see. You're using a Quality Factor of 1 to convert Sievert (equivalent dose) to Gray (dose). That makes nonsense of your calculation, unfortunately.
    You've quoted Zhang et al. several times, but I guess you missed the bit where they derive the correct Quality Factor:
    After conversion of the LET spectrum to LET in water, as discussed in Introduction, we obtain an average quality factor of Q〉= 4.3 Ī 0.7. After multiplication of the charged-particle absorbed dose rate (in water) measurement given above with Q, we obtain the GCR dose equivalent rate of 57.1 Ī 10.6 μSv/hour from charged particles.
    So we need to divide your erroneous factor of 9.5 by 4.3. So as I've pointed out several times already, the Chang'E-4 dose rate is about twice the old Apollo estimate for the 1969 lunar surface. Which is pretty much what the old Apollo radiation experts predicted for a solar minimum. (See, we're not comparing the 1969 value with the modern value--we're comparing the 1969 prediction of a solar-minimum value with a real solar-minimum value.)

    Anyway, back to my original question. Where is the contemporaneous dose measurement in cis-lunar space that convinces you the Chang'E-4 surface dose rate is higher than the dose rate in cis-lunar space?

    Quote Originally Posted by Lord Foul View Post
    So you do not believe this" Measurements taken by NASA's Lunar Reconnaissance Orbiter show that the number of high energy particles streaming in from space did not tail off closer to the moon's surface, as would be expected with the body of the moon blocking half the sky.
    ...
    Do I believe an unsourced quotation just because it's written in red? No, I don't.
    Do I believe a quote copied from the NBC website? No, I don't.
    As has been pointed out, the original data say something different from the journalist's interpretation. (This is probably more the rule than the exception when it comes to science journalism these days, sadly.)

    Grant Hutchison
    Last edited by grant hutchison; 2021-Apr-17 at 09:02 PM.

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    Quote Originally Posted by bknight View Post
    This is yet another false claim. Orion was intentionally aimed at the ,more dense portion of the VARB while Apollo traversed the a less dense part, just look at trajectories that Grant provided you.
    To be fair, I don't think I've posted an Orion orbit on this thread.
    You're maybe thinking of this old thread I started a few years ago: https://forum.cosmoquest.org/showthr...ight-be-useful

    It's kind of a cartoon Orion EFT1 orbit, with the right semimajor axis and eccentricity but deliberately matched in plane and apses with Apollo 11 for ease of comparison. But it does emphasize the very wide divergence between the two spacecraft.

    Grant Hutchison

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    Quote Originally Posted by Van Rijn View Post
    What, in your opinion, is the relevance of this statement to the current discussion? I have some suspicions on how you might be interpreting it, but I don’t want to put words in your mouth.
    I had made the claim that GCR was essentially unshieldable and that the Apollo had no shielding capable of attenuating it and this is me showing my reference.

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    Another important point from the Spence et al article linked above:

    https://agupubs.onlinelibrary.wiley....2/2013SW000995

    Here is a discussion of the nature of the radiation that would contribute to an astronautís absorbed dose, as per LRO measurements. Iíve bolded points of special interest:

    We use validated radiation transport models of the Cosmic Ray Telescope for the Effects of Radiation instrument and its response to both primary galactic cosmic rays (GCR) and secondary radiation, including lunar protons released through nuclear evaporation, to estimate their relative contributions to total dose rate in silicon (372 μGy/d) and dose equivalent rate at the skin (2.88 mSv/d). Near the Moon, we show that GCR accounts for ~91.4% of the total absorbed dose, with GCR protons accounting for ~42.8%, GCR alpha particles for ~18.5%, and GCR heavy ions for ~30.1%. The remaining ~8.6% of the dose at Lunar Reconnaissance Orbiter altitudes (~50 km) arises from secondary lunar species, primarily ďalbedoĒ protons (3.1%) and electrons (2.2%). Other lunar nuclear evaporation species contributing to the dose rate are positrons (1.5%), gammas (1.1%), and neutrons (0.7%). Relative contributions of these same species to the total dose equivalent rate in skin, a quantity of more direct biological relevance, favor those with comparatively high quality factors. Consequently, the primary GCR heavy ion components dominate the estimated effective skin dose.

    This is saying that about 91% of the radiation that would contribute to an astronautís absorbed dose near the Moon would be GCR, which is very significantly shielded by the Moon versus cislunar space versus 8.6% would come from secondaries. (Some radiation that is measured by the LRO would be blocked by a spacecraft, or a spacesuit so wouldnít contribute to an astronautís absorbed dose). I see no support here for the intensely radioactive lunar surface, supposedly increasing lunar radiation levels far above that of cislunar space, that LF has claimed.

    In fact, LF, Iíve seen no evidence at all for your claims of an intensely radioactive lunar surface. Do you have any?

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    Quote Originally Posted by Lord Foul View Post
    I had made the claim that GCR was essentially unshieldable and that the Apollo had no shielding capable of attenuating it and this is me showing my reference.
    First, are you claiming that a massive body like the Earth or the Moon could not block GCR? Because that would be utter nonsense. The practical issue for spacecraft is that the easiest way to shield from radiation is mass, and you want to minimize mass. Of course that doesnít apply if you use an entire world for shielding. Second, Apollo had some shielding and could attenuate lower energy particles. It didnít need to significantly attenuate high energy particles because that just didnít contribute enough radiation to add much risk on the short lunar missions.

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." ó Abraham Lincoln

    I say there is an invisible elf in my backyard. How do you prove that I am wrong?

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    Quote Originally Posted by grant hutchison View Post
    Oh, I see. You're using a Quality Factor of 1 to convert Sievert (equivalent dose) to Gray (dose). That makes nonsense of your calculation, unfortunately.
    You've quoted Zhang et al. several times, but I guess you missed the bit where they derive the correct Quality Factor:So we need to divide your erroneous factor of 9.5 by 4.3. So as I've pointed out several times already, the Chang'E-4 dose rate is about twice the old Apollo estimate for the 1969 lunar surface. Which is pretty much what the old Apollo radiation experts predicted for a solar minimum. (See, we're not comparing the 1969 value with the modern value--we're comparing the 1969 prediction of a solar-minimum value with a real solar-minimum value.)

    Anyway, back to my original question. Where is the contemporaneous dose measurement in cis-lunar space that convinces you the Chang'E-4 surface dose rate is higher than the dose rate in cis-lunar space?

    Do I believe an unsourced quotation just because it's written in red? No, I don't.
    Do I believe a quote copied from the NBC website? No, I don't.
    As has been pointed out, the original data say something different from the journalist's interpretation. (This is probably more the rule than the exception when it comes to science journalism these days, sadly.)

    Grant Hutchison
    .6mrad/hr = 6ugy/hr = 144ugy/day expected level. Actual level 10ugy/hr = 240ugy/hr/ 144ugy/day = 1.667 higher than expected? .24mgy is higher than .22mgy. It seems the moon would add a component of radiation to the overall in and above GCR. I am glad you guys straightened me out on this. I was thinking it was 6.7 times as high when it is only 1.66 times as high as expected. the article claimed 30 too 40% higher so I guess that checks out too.

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    Quote Originally Posted by Van Rijn View Post
    First, are you claiming that a massive body like the Earth or the Moon could not block GCR? Because that would be utter nonsense. The practical issue for spacecraft is that the easiest way to shield from radiation is mass, and you want to minimize mass. Of course that doesn’t apply if you use an entire world for shielding. Second, Apollo had some shielding and could attenuate lower energy particles. It didn’t need to significantly attenuate high energy particles because that just didn’t contribute enough radiation to add much risk on the short lunar missions.
    I made no such claim. The claim is we lack the technology to make shielding that can block GCR. The Apollo had no radiation shielding at all. It's structure and equipment provided it's only protection.

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    Quote Originally Posted by Van Rijn View Post
    Another important point from the Spence et al article linked above:

    https://agupubs.onlinelibrary.wiley....2/2013SW000995

    Here is a discussion of the nature of the radiation that would contribute to an astronaut’s absorbed dose, as per LRO measurements. I’ve bolded points of special interest:

    We use validated radiation transport models of the Cosmic Ray Telescope for the Effects of Radiation instrument and its response to both primary galactic cosmic rays (GCR) and secondary radiation, including lunar protons released through nuclear evaporation, to estimate their relative contributions to total dose rate in silicon (372 μGy/d) and dose equivalent rate at the skin (2.88 mSv/d). Near the Moon, we show that GCR accounts for ~91.4% of the total absorbed dose, with GCR protons accounting for ~42.8%, GCR alpha particles for ~18.5%, and GCR heavy ions for ~30.1%. The remaining ~8.6% of the dose at Lunar Reconnaissance Orbiter altitudes (~50 km) arises from secondary lunar species, primarily “albedo” protons (3.1%) and electrons (2.2%). Other lunar nuclear evaporation species contributing to the dose rate are positrons (1.5%), gammas (1.1%), and neutrons (0.7%). Relative contributions of these same species to the total dose equivalent rate in skin, a quantity of more direct biological relevance, favor those with comparatively high quality factors. Consequently, the primary GCR heavy ion components dominate the estimated effective skin dose.

    This is saying that about 91% of the radiation that would contribute to an astronaut’s absorbed dose near the Moon would be GCR, which is very significantly shielded by the Moon versus cislunar space versus 8.6% would come from secondaries. (Some radiation that is measured by the LRO would be blocked by a spacecraft, or a spacesuit so wouldn’t contribute to an astronaut’s absorbed dose). I see no support here for the intensely radioactive lunar surface, supposedly increasing lunar radiation levels far above that of cislunar space, that LF has claimed.

    In fact, LF, I’ve seen no evidence at all for your claims of an intensely radioactive lunar surface. Do you have any?
    Why do you think cislunar space radiation did not drop off approaching the moon as expected?
    Last edited by Lord Foul; 2021-Apr-17 at 11:05 PM.

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    Quote Originally Posted by grant hutchison View Post
    To be fair, I don't think I've posted an Orion orbit on this thread.
    You're maybe thinking of this old thread I started a few years ago: https://forum.cosmoquest.org/showthr...ight-be-useful

    It's kind of a cartoon Orion EFT1 orbit, with the right semimajor axis and eccentricity but deliberately matched in plane and apses with Apollo 11 for ease of comparison. But it does emphasize the very wide divergence between the two spacecraft.

    Grant Hutchison
    Consider the inclination angle of the Orion as compared to the Apollo lunar missions: https://history.nasa.gov/SP-4029/Apo...Orbit_Data.htm

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    Quote Originally Posted by Lord Foul View Post
    Consider the inclination angle of the Orion as compared to the Apollo lunar missions: https://history.nasa.gov/SP-4029/Apo...Orbit_Data.htm
    Both Apollo 11 and Orion EFT1 launched from Canaveral/Kennedy early in the launch window, so very similar inclinations in the region of 30 degrees.
    But I don't propose discussing Orion further. You've got a huge backlog of questions to respond to that relate to your original claims. Just as a reminder, here's mine:

    Where is the contemporaneous dose measurement in cis-lunar space that convinces you the Chang'E-4 surface dose rate is higher than the dose rate in cis-lunar space?

    Grant Hutchison

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    Quote Originally Posted by Lord Foul View Post
    I had made the claim that GCR was essentially unshieldable and that the Apollo had no shielding capable of attenuating it and this is me showing my reference.
    And this was addressed. You ignored the reply!

    Your question and request evasion continues and now you cite a paper that includes the implicit word "contains". Amongst other rays within its spectrum that CAN be shielded against!

    Question: Do you understand this?

    Or maybe this excerpt can get the penny to drop:

    "What is known with certainty is that the current radiation protection schemes do not completely shield the radiation spectrum encountered from the GCRs in the cislunar region and, in some cases, actually can be counterproductive and increase the hazard. "

    Not completely, no. But YOUR source refutes YOUR claim. No wonder you ignore this.

    You ignored the data showing how the average is massively skewed larger due to SPEs.
    You ignored the reference showing a massive difference between solar maximum 20 and 24.
    Now you're wittering on about Orion which is completely irrelevant.

    Answer the questions asked of you and give some rebuttal to the two MASSIVE points I have itemised.

    That is an official request for about the fourth time.

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    Quote Originally Posted by Lord Foul View Post
    .6mrad/hr = 6ugy/hr = 144ugy/day expected level. Actual level 10ugy/hr = 240ugy/hr/ 144ugy/day = 1.667 higher than expected?
    If you want to use that figure, then slightly lower than "expected". The Apollo radiation techs predicted an average 1.2 mrad/hr for the lunar surface at solar minimum, compared to this single measure of 1.0 mrad/hr from Chang'E-4.
    Now all we need is that contemporaneous measure from cis-lunar space, and we can see if their prediction of 2 mrad/hr was as close to being correct.

    Grant Hutchison

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    Quote Originally Posted by grant hutchison View Post
    If you want to use that figure, then slightly lower than "expected". The Apollo radiation techs predicted an average 1.2 mrad/hr for the lunar surface at solar minimum, compared to this single measure of 1.0 mrad/hr from Chang'E-4.
    Now all we need is that contemporaneous measure from cis-lunar space, and we can see if their prediction of 2 mrad/hr was as close to being correct.

    Grant Hutchison
    https://crater-web.sr.unh.edu/produc...=&screenwidth=

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