email - March 2014

Moon Rock Disequilibrium

Do uranium isotope ratios prove the Moon is young or old?

Neal sent us this email:

Wondering if the ratio of 234U to 238U of moon rocks has been measured a couple of times, and if this could be used as a proof of the moon being relatively young.

Since the moon is relatively airless and with negligible amounts of water, there could be no weathering or chemical processes which could account for the ratio to NOT be the expected 1 to 18,089 if it really were much older than 1.7 million years.

(none of the excuses used on earth could be rationally thought to be applicable to the moon)


Here’s a good example of a scientific prediction. As we explained in a previous article, 1 the ratio of uranium 234 (234U) to uranium 238 (238U) will reach equilibrium in 1.7 million years. If a rock containing uranium is older than 1.7 million years the ratio of 234U to 238U will have reached equilibrium. If it is much younger than 1.7 million years, the ratio will be close to whatever the ratio was when the rock was created (which could be any value).

Evolutionary prediction: If the Earth is 4.6 billion years old, the ratio of 234U to 238U should have reached equilibrium long ago. On Earth, the ratio has been measured to be out of equilibrium many times, contradicting the evolutionary prediction.

Neal correctly observes that the evolutionists’ usual explanation for why uranium isotopes are not in equilibrium on Earth (transport by water) doesn’t apply to the Moon. So, Neal wonders, “Did analysis of moon rocks confirm the predictions of the Old Moon theory?” The short answer is, “No, but only three moon rock isotope ratios have ever been analyzed.”

Here’s the long answer: As we told you in a previous article, 2 the Apollo 11 moon rocks were analyzed very carefully in 1969, resulting in a special report in 1970. Only one of the articles in that special report refers to 234U. It says,

The 234U daughter is in radioactive equilibrium with parent 238U within experimental error of +1.5 percent. …

Although, within experimental error, 234U is in radioactive equilibrium with 238U, preliminary data indicate a value for the 230Th/238U activity ratio that is greater than unity [that is, NOT in equilibrium] in three of the samples analyzed (10017, 10020, 10057). A 228Th/232Th activity ratio of unity would indicate that 228Th is in radioactive equilibrium with parent 232Th. In two of the rocks (10020, 10057) the 228Th alpha activity was measured to be about 10 percent greater than the 4.0-Mev alpha activity of 232Th. The reasons for these variations are not understood at this time. 3

In plain English, the 234U/238U ratio was equal to the evolutionists’ predicted value in the three Apollo 11 moon rocks analyzed—but the 230Th/238U ratio was not the predicted value in any of those three rocks. Furthermore, the 228Th/232Th ratio was the predicted value in one of those three rocks; but not the predicted value in the other two.

In summary, three different isotope ratios were measured in all three moon rocks. In the first case, 3 out of 3 ratios were consistent with the evolutionists’ Old Moon theory predictions. In the second case, 0 out of 3 ratios were consistent with the Old Moon predictions. In the third case, the ratio was consistent with the Old Moon predictions in just 1 of the 3 rocks. So, a total of 4 out of 9 ratios were consistent with the Old Moon predictions, and 5 out of 9 ratios were not what one would predict if the Moon is more than 1.7 million years old. As the report says, “The reasons for these variations are not understood at this time.”

Of course, if the Moon is only a few thousand years old, the isotope ratios will still be close to whatever they were when the Moon was created, and could be anything. The measured ratios are consistent with the Young Moon predictions. But, to be fair, a sample size of only three rocks is not conclusive.

Down to Earth

When searching for articles about uranium disequilibrium on the Moon, the search engine came up with LOTS of articles about uranium disequilibrium on Earth, dating back as far as 1963.4 (The “Atomic Age” was just beginning in the 1960’s, so there were many research papers published about uranium back then.) For more than 51 years, isotopic evidence reported in the peer-reviewed professional literature has been overwhelmingly against the Earth being millions of years old; but this is not known by people like Bill Nye because the evidence against evolution is withheld from students in public schools.

The large variation in the ratio of uranium-234 to uranium-238 (234U/238U) in rivers is not well understood, … The energetic alpha decay of 238U makes its great-granddaughter, 234U, relatively mobile and causes variability in the ratio of activities of 234U and 238U (234U/238U) in the surface-Earth environment. Rivers, for instance, have (234U/238U) varying from <1 [less than equilibrium] to >3 [more than 3 times equilibrium]. 5

Radioactive disequilibrium is seen in nature under many conditions among the members of the uranium and thorium decay series, in each of which alpha decay plays a prominent role. Earlier experiments on a specialized material demonstrated the presence of at least two distinct mechanisms for such separations of isotopes from their parents. Both are the result of recoiling, alpha-decaying nuclei. One of these, direct ejection of the recoiling nucleus from a grain, is physical, depends largely on the stopping power of the surroundings, and hence is insensitive to the detailed geochemical environment.

If this behavior is general to uranium-bearing minerals, it is adequate to cause the observed 234U/238U anomalies which appear over geological times. 6

Let’s try to explain that in plain English. When the “geochemical environment” (that is, water) flows over rocks containing uranium, some of it dissolves in the water. The ratio of isotopes in the water should be the same as the ratio in the rocks, which should be the equilibrium ratio if the Earth is old—but the measured ratios often aren’t even close to the predicted value. Therefore, evolutionists think (without evidence) that some uranium isotopes must dissolve more easily than others, causing rocks and water to have too much (or too little) of particular isotopes because they have been moved by water.

Fleischer didn’t buy that theory, so he proposed his alpha recoil theory. When you shoot a rifle, the bullet goes forward, but the recoil pushes you backward. Fleischer’s theory is that when a 238U atom shoots out an alpha particle to become a 234U atom, the 234U atom might get knocked backwards out of the crystal containing it and wind up in a neighboring crystal. That’s why some crystals might have more or less 234U than expected.

The problem with Fleischer’s theory is that there is no reason to believe there is a preferred direction for the recoil. It is equally likely for a 238U atom to eject an alpha particle to the south as to the north. Therefore, the number of 234U atoms that are knocked from a north crystal to a south crystal is, on average, going to equal the number of 234U atoms that are knocked from a south crystal to a north crystal. It won’t affect the equilibrium.

The only reasonable explanation for radioactive isotopes on the Earth and on the Moon to be out of equilibrium is that they weren’t in equilibrium when they were created, and have not had time to reach equilibrium since then.

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1 Disclosure, July 2012, “U-Series Dating”,
2 Disclosure, June 2008, “The Age of the Moon”,
3 Mitsunobu Tatsumoto and John N. Rosholt, Science, 30 January 1970, “Age of the Moon: An Isotopic Study of Uranium-Thorium-Lead Systematics of Lunar Samples”,
4 Rosholt, et al., Science, 18 January, 1963, “Isotopic Fractionation of Uranium in Sandstone”,
5 Robinson, Science, 6 August, 2004, “Climatic Control of Riverine and Seawater Uranium-Isotope Ratios”,
6 Fleischer, Science, 29 February 1980, “Isotopic Disequilibrium of Uranium: Alpha-Recoil Damage and Preferential Solution Effects”,