- For the founder of the Unification Church, see Sun Myung Moon
A moon is a natural satellite orbiting a planet. The Earth's only moon is known rather unimaginatively as "the Moon". Being the most noticeable object in the night sky, 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 relatively large compared to its parent body (the Earth), which makes it somewhat unique in the Solar System, though the former planet Pluto and its moon Charon are in a similar situation. the "near side"
The Moon's period of rotation around its own axis is equal to its period of revolution around the Earth. As a result, one of the Moon's hemispheres is permanently facing the Earth, though one can actually see more than a half of the Moon's surface due to libration. This synchronization is caused by the gravitational interaction of the Earth and the Moon, in a process known as "tidal locking". This is not unique to the Earth-Moon system though and many other moons in the Solar System are tidally locked or near-locked to their parent bodies.
The hemisphere facing the Earth is known as the "near side" and the other one is called the "far side". There is no "dark side of the Moon". Both "sides" experience day and night, which is what causes moon phases (with a full moon being the result of sunlight hitting all of the near side; the sun only hitting the far side results in a new moon). The only difference is that on the near side it is a little bit lighter during the night (new moon) due to the illumination provided by the sunlight reflecting off the Earth.
It is thought that the moon may be very important in the development of life, as the tidal activity caused by its gravity essentially churns the oceans, mixing up the chemical ingredients that would have caused abiogenesis to occur.
The Moon: proof of creationism?
In a word, no. It isn't, although it's been touted as one.
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!"
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. Deal with it.
The Moon, as the second most hallowed object in the sky, is honored by having first (or second, depending on your calendric issues) day of the week named after it: Monday.
Occasionally the Earth gets between the sun and the moon, temporarily darkening the moon. Sometimes the moon gets revenge for this by preventing some sunlight from reaching the Earth by getting in front of the sun and causing a solar eclipse. (It isn't particularly good at this since only a small part of the planet can see a total eclipse.)
Amaze your friends and win free beers for yourself, by taking bets that the Earth has more than one moon. Once everybody is expecting a pint from you, look really smug and say, "What about Cruithne then?" Enjoy your beers. Unless your friends (rightly) point out that 3753 Cruithne is actually an asteroid in orbital resonance with Earth, and then beat you up for not buying the 14 pints you owe.
- ↑ 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.
- ↑ See the Wikipedia article on Libration.. It has a nice animation showing the libration of the Moon over a month.
- ↑ 3.0 3.1 See the Wikipedia article on Tidal locking. It has a list of tidally locked moons in the Solar System.
- ↑ See the Wikipedia article on Earthshine.
- ↑ Earth's "second" moon