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Unsolved Mysteries of Moon Observations and Transient Lunar Phenomena

Leonard Kelley holds a bachelor's in physics with a minor in mathematics. He loves the academic world and strives to constantly explore it.


The moon has been the focus of many of man’s efforts, and with the dawning of the telescope, that reach was pushed to new levels. People began to map the surface of the moon in great detail, and from these observations, some strange happenings were found. Whether they have a natural explanation or were the clever but untrue connections our brains sometimes make for us is open for the reader to determine. But here are a few selections into mysterious moon observations of the past and present.


On April 19, 1787, Herschel (discoverer of Uranus) spotted three red glowing spots in a dark region of the moon. From Herschel’s perspective, he theorized they were volcanoes and compared the brightness of the spots to a comet spotted nine days prior by Pierre-Francois. He found that the magnitude of the spots was on par with a “dim naked-eye star,” but we know that there are no volcanoes on the moon—so what did Herschel see? There was a lot of solar activity at the time that produced aurora, but to have this so far from the arctic is unlikely. An interaction between the surface and solar wind has also been postulated (Seargent 6-7).


In 1866, Schmidt was observing the Linne crater and noting that it didn’t seem definite but instead was like “a whitish cloud.” Others took a look at the crater but didn’t see anything unusual about it. It was notable because Schmidt was an established astronomer and was not prone to making mistakes. It was a genuine curiosity for the science community as to what he saw (Trident).


From 1919 to 1924, Pickering saw dark areas that seemed to change in size on the moon’s surface, which he believed to be the result of a living presence. He also spotted bright changes at various points on the moon and postulated that they were volcanoes. But with no one seeing these amazing things at the time, the most likely explanation was that Pickering had floaters in his eye(s) (Seargent 7-8).

Astronomer Leon Stuart’s photo of the Moon with a mystery white speck, taken on November 15, 1953.

Astronomer Leon Stuart’s photo of the Moon with a mystery white speck, taken on November 15, 1953.

The Culprit

Sir Patrick Moore developed the idea of transient lunar phenomena (TLP) in 1968 to explain these observations. He himself spotted one in the Linne crater just like Schmidt did, and eliminated the possibility of telescope error when he spotted the luminance with three different scopes. So what could be the underlying cause to these sightings? Hints have been scattered here, with the outflows of gases and the high solar activity kicking up dust. NASA decided to look into it prior to the moon landing in case something was dangerous and could adversely impact the Apollo missions. In their effort, entitled Project Moon-Blink, they looked at the 579 known TLPs seen from 1540 to 1967 as well as then-current sightings and found that red discolorations did indeed happen, with a significant sighting seen during the Project on Nov. 15, 1965, that lasted for hours before becoming unobservable as the sun rose (Armagh, Seargent 19, Trident).

The outgassing theory would result from subsurface pockets being released via tidal interactions. These gases could come from the decay of radioactive particles, and evidence from Apollo 15 indicates this. NASA also spotted a red TLP and noted a spike in alpha particles, a tell-tale by-product of the decay of Radon-222 (known to be on the moon). Another possibility is a meteorite vaporizing material upon impact and driving an energetic show. Electromagnetic considerations may also play a role, with a charge buildup in surface dust being released by solar activity (Armagh).

The impact of a large meteorite on the lunar surface on the 11 of September in 2013.

The impact of a large meteorite on the lunar surface on the 11 of September in 2013.

Aristarchus Crater

Any type of clustering in sightings would be significant because one would expect a rather random distribution across the surface of the moon. This has not been the case. During Moon-Blink, NASA discovered that almost a third of the known sightings at the time came from the Aristarchus crater. The first known sighting was on February 4th, 1821, by Captain Kater and several more were seen for the next 100 years. Many described the event as resembling a star appearing momentarily in the crater or a wall being illuminated (Armagh, Hanks).

The first notable modern observation of the event took place on October 13, 1959, when E.H. Rowe looked at the crater through his 36-inch telescope. He also saw the white flash, but unlike others, he also spotted a reddish glow that was at the perimeter of the white flash. It lasted a few seconds, then only the normal glow remained. Just over 4 years later, on October 29, 1963, James A, Greenacre and Edward Barr (both at Lowell Observatory) examined the crater. They too saw red, orange, and pink colors but did not secure any pictures. However, Greenacre was established as a well-respected lunar expert, so the findings had some weight to them. And a few days later, on November 1 and 2, 1963 Zdenek Kopal and Thomas Rackham see similar luminescence on the moon and were able to photograph them. These findings were published in Scientific American that year, and more and more sightings of the event were being recorded by others. Astronauts even got a first-hand view of this. During Apollo 11, NASA was told that a TLP was happening at that moment in the crater. They asked the Apollo 11 crew to look at the crater from their vantage point and found that indeed the general area seemed to glow (Seargent 14, Hanks).

The usual theories came into play with the crater to explain its glowing aspects, and it should be noted that Aristarchus has some interesting properties in and of itself that make the seemingly anomalous clustering make more sense. For starts, its albedo (reflectivity) is much higher than its surroundings. Also, it has a central peak in its center that is rather high, catching lots of sunlight and adding to the contrast of its surroundings. And it’s in a prime viewing spot, being easy to spot and also visually interesting to look at. All of these make it a prime location for seeing TLPs (Hanks).

Alphonsus Crater

This is another crater with a history of TLPs. On October 26, 1956, Dinsmore Alter took a near-UV picture of the crater and noticed that the bottom was all blurry. Based on how the picture was taken, only an ionizing atmosphere would account for the sighting seen, meaning some outgassing was occurring at the time. On November 2, 1958 Mikolai A. Kozyrev saw an “eruption” near the high point on the Alphonsus crater for about 30 minutes. And fortunately, the 48 inch reflector he was using had a spectrometer so he was able to gather chemical information on what he was seeing. His data indicated that it was mainly C2/C3 molecular gas and the spectrum had a peak near the center and was white in appearance. The brightness then decreased until the normal albedo was restored. Scientists wondered if an outflow of gas from below the surface was the culprit, but why would it happen then? Maybe it was a comet impact, which would explain the carbon seen but the odds of one hitting the moon are quite low. Another point against this was how Kozyrev spotted further activity at the same spot on October 23 1959 (Seargent 13, Trident).

Enduring Mysteries

Thus far, no scientific consensus has been reached on the subject. Some have noted that the number of known sightings has dropped since the 1970s, perhaps because of improvements in technology or because of a lull in lunar activity. Who knows, but surely as the years go on, we will find more data that will enable us to reach our conclusion(s) about what caused TLPs.

Works Cited

Armagh Observatory. “Whatever happened to transient lunar phenomena?” Armagh Observatory and Planetarium, 27 Feb. 2014. Web. 25 Sept. 2018.

Hanks, Micah. “The Aristarchus Anomaly: A Beacon on the Moon?” 8th Kind Pty Ltd, 28 Nov. 2013. Web. 25 Sept. 2018.

Seargent, David A.J. Weird Astronomy. Springer, New York. 2011. 6-8, 13-4, 19.

Trident Engineering Associates. “Project Moon-Blink.” NASA. October 1966. Print.

© 2019 Leonard Kelley


DavidoDave on September 12, 2019:

"Unsolved..."? The masses are certainly told many things, and, 'unsolved', or 'unknown' are the favorites to keep info just 'curbed' enough for many to lose interest. THE favorite, of course, is, 'it's not possible..." Think 30 - 50 yrs in the future, then, realize it already exists, just not for the public. So, whenever we see things happen that don't have a true explanation, and they are 'shady', think, the future is now for some, and think of who could be benefiting while the masses crawl through the mundane existence; miracles, wonder, amazement, etc. are all around us, but, we fail to see because our attention is always on the lesser important (but, seemingly, important) issues.