"There's a lot we know about the moon. It's roughly one-sixth the size of the Earth; it's about 4.6 billion years old; it's approximately 238,000 miles distant from the Earth; it has no atmosphere and no water (except what was recently found to exist as ice in craters near the poles); it's covered with an incredibly fine gray powder. We've walked on the moon six times during the Apollo missions, and we've sent many more probes there to map it and study it.
But there's much we don't know about it, too. We're not sure where it came from. Some think it might be a broken-off chunk of Earth. Although there's evidence that the moon once had active volcanoes, we're not sure if it's still geologically active (the prevailing theory is that it is not).
The moon has its more controversial mysteries, too. Some think extraterrestrials have or once had bases there. Some think there's stuff on the moon -- other than the hardware, flags, and debris left there by the Apollo astronauts - that the US government knows about, but is not telling us. Decades - even centuries - before we sent ships to the moon, observers with telescopes have claimed to see signs of intelligent life or design there. Indeed, there are many enigmatic photos that seem to show shapes and structures on the lunar surface that don't fit conventional explanations. Perhaps there are reasonable answers for them, but those answers are not easy to find."
Here's a look at some of those lunar anomalies:
The Shard.
This one, in a photo snapped by the Lunar Orbiter, has been named "the shard" or "the tower," by Richard C. Hoagland, who comments on this photo at Richard Hoagland's Lunar Anomalies. Taken from a distance of about 250 miles, the strange structure (if that's what it is) would be enormous - seven miles high, by Hoagland's calculations. (The star-like shape above the tower is a camera registration mark.) It's difficult to believe that such a huge structure actually stands on the moon... so what are we seeing in this photo? Is it a plume of "smoke" from some lunar gaseous emission? Are we seeing the ejecta from a meteorite impact? What is it?
The Castle
This strange object, photographed during an Apollo mission, has been named "the castle" by Hoagland. It seems to have a definite structure, like the remnant wall of some ancient building. The bottom looks as if it has rows of support columns, above which is a high spire. Whatever it is, it's much brighter than the surrounding landscape. Is it just a trick of light and shadow? A photographic anomaly? Or is it all that remains of some rich Martian's get-away retreat?
The Ukert Crater.
The Ukert crater, located near the center of the moon as it is viewed from the Earth, contains this amazing equilateral triangle. According to Luna: Arcologies on the Moon, each side of the triangle is 16 miles in length. And note the three bright objects around the perimeter of the crater - if they are joined by straight lines, they too would from an equilateral triangle. Is this evidence of intelligent design, or merely a fantastic coincidence?
Strange Reflection.
This is one of my favorites because it comes directly from a famous photo from the second Apollo mission to land on the moon, Apollo 12. The photo is of astronaut Alan Bean and was taken by Pete Conrad as both stand on the lunar surface. You can see Conrad in the reflection in Bean's visor. You can also see some instrumentation in the foreground of the reflection. But what the heck is that thing hovering in the sky in the background, pointed out here as "artifact" by Luna: Astronauts Among the Ruins? You can even see the shadow it casts on the ground behind Conrad. It's been seen as everything from a UFO to a hanging light fixture by those who think the Apollo landings were faked. Yet this photo is really puzzling. We can usually find reasonable, or at least plausible, explanations for the other photos shown here and elsewhere, but this one is truly enigmatic. What about it NASA? What the heck is that thing?
As mentioned above, strange things have been seen on the moon for centuries -- usually flashes of light or color, or lights that appear to move across the lunar surface. These are known as transient lunar phenomena (TLP), and many of the reports, dating from 1540 to 1969, have been cataloged by NASA. But perhaps the best source for this kind of information is The Lunascan Project, an organized effort by amateur astronomers to record and document TLPs.
