| Style over substance|
A moon is a natural satellite orbiting a planet. The Earth's only moon is known rather unimaginatively as "the Moon" (or sometimes Luna if you're feeling fancy, like science fiction or speak Spanish.) Being the most noticeable object in the night sky, if it is even out that is, it is a subject of much woo, particularly in astrology where it is usually given a female quality and a high degree of importance in the sky.
The Moon is one of the largest natural satellites of the Solar System with a diameter of almost 3,500 kilometers, but even with that size it has just 1/81 of the Earth's mass. It has very little atmosphere.
As even a casual glance with binoculars can show, the Moon is pockmarked with a whole lot of craters caused by asteroid and comet impacts of all sizes from tiny microscopic ones found on lunar rocks brought by the "Apollo" missions to large, multi-ringed, basins with diameters of up to 2,500 kilometers. The crater-saturated areas that are visually pale are known as "terrae" while the large, dark, areas that form the "Man in the Moon" and are known as "seas", as they were thought centuries ago to be that but are currently known to be plains of solidified lava that covered previous crater-filled areas back in the young days of the Moon.
As the first two images that illustrate this article show, the lunar far side, entirely unobservable from Earth except when librations allow us to see a small part of it, has a very remarkable paucity of "seas," which has been attributed to a thicker crust inhibiting lava from oozing to the surface. The lack of mares shows how severely the Moon (as well as other planets and moons) was whacked during the formation of the Solar System. Note that the far side is not dark as is often thought, as the Sun shines there as much as on the near side — the only difference is the lack of Earth hanging upon the moonscape, and "dark" is both in the sense of being unknown until spacecraft charted it and that communications with spaceships there are blocked by those thousands of kilometers of Moon rock unless one uses a relay satellite, as the Chinese with their Chang'e 4 lander and the Queqiao.
Creationists argue that the moon proves young Earth. In a word, no.
The Moon has been a source of astronomical study for at least three millennia. To say that science has failed to explain key elements of lunar motion, geography, or composition, is to be willfully blind. Nonetheless, many creationists fabricate "errors" in scientific studies of the Moon, and suggest that, since science has failed, the only alternative is creationism. This is gap-filling with God to an absurd degree. Assuming, for once, that science could not explain the Moon, this does not imply that the only explanation is God. Science evolves. Not everything is known now, nor should science be forced to prove the universe to disprove creationism. The standard for evaluating creationist claims about scientific disciplines is the same that applies to all scientific theories: does the claim match the evidence? Regarding creationism, the answer is a resounding "no!"
Creationist claims surrounding the moon:
- Lunar recession (the moon is going away from the Earth too fast)
- Lunar dust (there's not enough moon dust)
- Lunar formation (the moon couldn't have formed)
- Lunar radioactivity (the moon is too hot)
- Atmosphere of the Moon (there's too much moon gas)
- Lunar transient phenomena (the moon is too active)
- Lunar bukkake hypothesis (the moon got shot with water during the Flood)
Moon landings and the idiots that claim they are a hoax
Twelve American astronauts landed on the Moon between 1969 and 1972, took pictures, left behind some junk, and came back home with some rocks. Deal with it.
The moon gives off light
It seems natural enough for pre-scientific cultures to assume that the sun and the moon both give off light. However, this is not true; the moon is a reflector of light, not a generator, save as a black body, and in that sense, everything gives off light. A good example of this is Genesis 1:16, in which god creates "a greater light to rule the day" (the sun) and "a lesser light to rule the night" (the moon). So there goes any claim that Genesis is scientific. Even so, the moon appears during the day and not in the night at all depending on what phase it is currently in, so it doesn't necessarily rule the night either.
Bill Nye the Science Guy took the bible to task on this one. It wasn't popular.
The moon's light is not actually blue, but perceived as blue due to the Purkinje effect.
Nevertheless, some truly dedicated followers of the "TEH QUR'AN IS TOTES SCIENCE" argument have still tried to prove it. A few of them stoop to using an article proposing that NASA found a crack that ran all the way around the Moon -- this argument is a total fraud, as anyone with a non-Qur'an-addled brain can spot.
Many Islamic scholars believe that this verse is best understood as a statement of something to occur at the final judgment. This is supported by the fact that the Surah concerns itself with that judgement, and the references to previous judgements are in the middle part of the Surah, and also that the immediate context of the verse makes a future rather than past interpretation more likely. While there is weak support in the Sunnah for a literal past tense interpretation of the event, even in that case, a plausible interpretation would include the possibility of e.g. a large asteroid impact providing the appearance of the Moon splitting (contemporary writings from India record one such event). It should also be noted that the writing here is poetic, so what exactly "the Moon is cleft asunder" indicates is uncertain and based on the Arabic is just as likely to have a metaphorical meaning. In other words, there is no single interpretation of what exactly this verse refers to. If taken literally it refers to some obvious sign in the moon, figuratively it would likely refer to Islam "tearing assunder" the religious fabric of the Middle East (if past tense) or the world (if end times was meant).
Other Muslim apologetics claim that, when Muhammad put the Moon back together, there was no crack because it was joined together perfectly, molecule-to-molecule. This is special pleading on a grand scale and should be ignored.
Apparent size and the idiots that claim Aliensdidit
It is a fact that the geometry of the Earth-Moon-Sun system is such that the apparent sizes of the Sun and the Moon, as seen from here, are very close to the same. During a total solar eclipse it is often the case that the Moon sits right on top of the Sun like two stacked pennies (not always, however — sometimes the Moon is at apogee and an annular eclipse is the result. Like a US quarter (24.26mm) stacked on a UK 2p (25.9mm).)[note 2]
Astronomers tend to just accept this as a fact of nature. Pseudoastronomers, when lecturing to, say, MUFON interest groups, are likely to cue up the Powerpoint™ slide and say "Can this be coincidence? I THINK NOT!" The extremist pseudoastronomical position is that the Moon is obviously artificial, towed carefully into place by Aliens.
The moon is quite definitely made of cheese. Wallace and Gromit proved it.
- Luna, er, the Moon at that other Wiki for much, much more.
- Pictured here is the near side, which faces Earth constantly and is completely visible during a full moon. The far side doesn't have nearly as much of the darker spots that the "man in the moon" is made of so it's more pale and boring.
- If you want to get all accurate about it, here are the numbers:
- Moon -- 29.3 minutes of arc at apogee, 34.1 at perigee
- Sun -- 31.6 at Earth's aphelion, 32.7 at perihelion
- So it can also happen that the Moon appears too big to stack on the Sun