is it coincidence that the moon rotates once every full orbit of the the earth?
404104
This situation is the natural result of one body orbiting another.  It is called tidal locking.  All of the moons of Jupiter are tidally locked to it, and Pluto and it's moon, Charon are tidally locked to each other for example.\n\nWhat happens is that an object that is rotating faster than it is orbiting feels a torque from the tidal force (differential gravity) exerted across it by the object it is orbiting.  Over time this will cause the rotation period to slow down to match the orbital period.  The time this takes depends on the distance between the two bodies and the reletive masses, as well as a few other factors.
9375
While the Moon does rotate, it is tidally locked to the Earth.  This means that we always see the same side of the Moon.\n\nThis happens when two astronomical bodies closely orbit each other.
187789
In fact, million years ago, the moon's rotation is not exactly in sync with it's revolution, it's rotation was faster back at those days and the rotation is not synced. It is because of the relational effect of the gravity of earth to moon that slowed down the moon to a stop and synced its rotation to earth's revolution. It is not purely a coincidental as a lot of moons of other planets is also "phase locked" to the planet's it's revoluting
310923
It's orbit is closer to a circle than any other with an eccentricity of less that 1%. It also has a retrograde motion (it rotates from east to west instead of west to east). It always shows the same face to earth in the same way the moon does.
10311
You only see one side of the moon from the Earth because the moon spins and rotates at just the right speeds.  As the moon revolves around the Earth it also spins around it's axis.  These two speeds happen to be just right so that the same side of the moon is always facing the Earth.  The phases of the moon are caused by the Earth casting a shadow on the moon, you can only see the part of the moon that's reflecting light from the Sun.
723622
The phases of the moon are the same around the world. What varies is the rise and set time. The US Naval Observatory is a great site for this.
280642
It is a coincidence.\n\nThe sun is much larger than the moon (~400 times), and yet the moon is much closer than the sun (~400 times).\nIt is remarkable coincidence that right now, as seen from the Earth, both the moon and the sun appear the same size.\nIt will not stay this way forever, the moon is very slowly moving away from the Earth, eventually it will get far enough away that it will look smaller than the sun and there will be no such thing as a total solar eclipse.
537473
There is something to this.  The net angular momentum of the Earth-Moon system is such that it is fairly stable to the small torques introduced by other planets.  For instance, the orientation of Mars' rotational axis is believed to have changed dramatically over time.  This is shown with numerical models. \n\nThe moon is moving farther away from the earth.  Angular momentum  is transfered by tides.  The tidal bulge of the Earth remains oriented towards the moon.  The earth rotates under this bulge and drags it forward a bit. The gravity of the bulge itself then pulls the moon ahead in its orbit some.  The net effect is the earth's rotation slows, and moon moves to a slightly larger orbit.\n\nAt some point, the Moon's orbital period will be the same length as the Earth's rotational period and the Earth and moon will be tidally locked to one another. \n\nRegardless, the entire system will still have a lot of angular momentum and the Earth will be fairly immune to significant changes to the obliquity of its rotation.
738089
Just as the moon can cause tides in the Earth's oceans due to gravity, the Earth can also cause tidal effects on the moon.  Over time, these effects have caused the moon to become "tidally locked".  This has the effect of causing the moon's rotation period to equal its revolution period.  You can see this effect by having someone walk around you but looking directly at you.  While they are facing you, the actual direction of their face changes as they move around you.\n\nHowever, the moon's orbit is not perfectly circular.  It is a slight ellipse so, sometimes, its rotation can get a little ahead or behind of its orbital position.  Also the orbit is tilted with respect to the Earth's equator.  These combine to allow us to see about 55 -60 % of the moon's surface during the orbit although, of course, we can only see half at any given time.
1116527
The Moon rotates at just the right speed so that it always keeps one face pointed toward the Earth. Almost all moons in the Solar System keep one face pointed toward their planet. \n\nThe moon rises in the east, and sets in the west. It moves from east to west, right? If you think about it, you should realize that much of the moon's apparent motion is due to the spin of the earth. The moon appears to go around the earth about once a day. And, you probably know that the moon actually takes about a month to go around the earth. That's where we get the word "month."\n\nWhy don't you perform a simple observation. Look at the moon, some night, and see where it is with respect to the stars (or with respect to the sun). You don't need to know the stars very well, but you probably want to ignore the planets (Venus, Jupiter, and Mars, mainly, as their motion complicates this observation). Night after night, the moon moves against the background of stars. See if you can tell which way the moon is moving, against the background of stars.\n\nAnother simple observation would be to keep track of when the moon rises (roughly) or sets from night to night. Does it rise later each night, or earlier, or what?\n\nYou will see that the moon moves west to east, fairly rapidly. \nWhich way does the earth spin? Well, the stars, sun, moon, and planets all seem to be moving east to west. So the earth is spinning in the opposite direction, west to east. Hey, the moon is also moving west to east, coincidence? Well, the earth is moving around the sun from west to east. In fact all nine of the planets are moving around the sun from west to east. And, all of the planets, except Uranus (which is lying on its side) and Venus (which is spinning slowly backward), are rotating from west to east. And most of the moons, of the various planets, are orbiting their planets from west to east. And most of the asteroids are orbiting the sun from west to east.\n\nIt's not a coincidence. The Solar System started out as a cloud of dust and gas, and it was rotating from west to east. That's why most of its parts are still rotating and orbiting from west to east.
700627
The rotation of the moon just happens to be in the same sync as its orbit around the earth, so we only see one side. From the looks of the moon, though, it's speculated that the moon may have orbited faster or rotated faster, etc because there are crater marks on the earth side also, just not as many.\n\nActually, the moon is locked in its orbit so it always faces the Earth. The Moon is NOT perfectly round...technically its shaped like an egg due to the effects of gravity from the earth and possibly too when the moon was formed bilions of years agao after a huge meteor crashed into the earth and some of the Earth's molten core spewed out into space. Because the Earth is more massive than the Moon, it pulls on the Moon, "stretching" it closer to the Earth, throwing the shape and axis off, causing the moon unable to rotate on its own axis. This same effect is seen by the moons of other massive planets like Jupiter and Saturn. The same is effect is also seen with Mercury due to its close proximity the Sun and its massive gravitational effects.
131965
well actually, it depends where you are on the moon.\nIf you are on the back side, away from earth, you will never see the earth, since that side never faces earth. you would need to walk? drive? around to the side that does face earth, and then yes, you could watch the entire earth sping by, once every 24 earth hours.
453034
Full moon\n\nThe Galileo spacecraft took this composite image on 7 December 1992 on its way to explore the Jupiter system in 1995-97. The color is 'enhanced' in the sense that the CCD camera is sensitive to near infrared wavelengths of light beyond human vision.The Full Moon is the lunar phase that occurs when the Moon lies on the opposite side of Earth from the Sun. The Moon as seen from the surface of Earth is fully illuminated by the Sun at this time, presenting a "full" round disk to viewers on Earth. As always, only half the total surface of the Moon is illuminated.\n\n\n1 Eclipses \n2 Numbers and formulae \n3 Folklore \n4 Calendars \n5 Full Moon names \n6 The Blue moon \n7 See also \n8 References \n \n\n\n\nEclipses\nA Full Moon is the only time when a lunar eclipse is possible; at that time the Moon may move through the shadow cast by Earth. However, because of the tilt or inclination of the Moon's orbit around Earth relative to Earth's orbit around the Sun, the Moon usually passes to the north or south of Earth's shadow at Full Moon, so a lunar eclipse does not occur at every Full Moon.\n\nFull Moons are generally a poor time to conduct astronomical observations, since the bright reflected sunlight from the Moon overwhelms the dimmer light from stars.\n\n\nNumbers and formulae\nAlthough on average it takes only 27.322 days (sidereal month) for the Moon to complete one orbit around Earth, it requires about two more days than that to again catch up with the Sun. On average, the number of days between Full Moons is about 29.5306 days. The actual number of days may differ from the average number by more than a half day. From one Full Moon to the next, the number of days in one lunation can vary between 29.272 and 29.833 days.\n\nThe age and apparent size of the Full Moon vary in a cycle of just under 14 synodic months, which is called the Full moon cycle.\n\nThe combined date and time of Full Moon number N, using a fictitious moon that moves at a strictly mean rate is approximately:\n\nD = 20.362954 + 29.5305888531 × N + 102.19 × 10-12 × N 2 \nD is the number of days (and fractions) since 1 January 2000 00:00:00 UTC, \nN is the count of full moons starting with zero as the first (not 1 as you would have expected) as the first Moon in the year 2000. \nThe true Full Moon may differ from this by up to about 14.5 hours, due to the normal irregularity in the Moon's Keplerian orbit, and due to the periodic perturbations on that Keplerian orbit by the Sun, the equatorial bulge of Earth, and nearby planets.\n\nSee the New Moon page for a detailed explanation of the formula.\n\n\nFolklore\nFull Moons are traditionally associated with temporal insomnia, insanity (hence the terms lunacy and lunatic) and various magical phenomena such as lycanthropy.\n\nPsychologists have found that there is no strong evidence for effects on behaviour around Full Moon [1]. They find that studies are not consistent, with some showing a positive effect, while others will show a negative effect. In one instance, the December 23, 2000 issue of the British Medical Journal published two studies on dog bite admission to hospitals in England and Australia. The study of the Bradford Royal Infirmary found that dog bites were twice as common at Full Moon, while the study of public hospitals in Australia found they were less likely at Full Moon. Psychologists point out that there is a difference between correlation and causation. The mere fact that two events happen at the same time doesn't mean that there is a cause and effect relationship between the two.\n\nNeopagans hold a monthly ritual called an Esbat at each Full Moon.\n\nMany people practicing traditional Chinese religions prepare their ritual offerings to their ancestors and deities on every Full Moon and New Moon.\n\n\nCalendars\nThe Islamic calendar and the traditional Chinese calendar are both based on the phases of the Moon. Neither calendar, however, begins i
47510
The moon DOES rotate.  The reason you cannot detect it is because it is in a synchronous rotation, meaning that it takes the same ammount of time to revolve as it does to rotate, meaning that the same face (the Light side) is always facing us.  It may be hard to visualize at first, but imagine you are the moon.  Now, stand facing an object, like a pole which will be the Earth.  Now, practice spinning around (revolving) so that you can do it in exactly 10 seconds.  Now, practice walking around the pole so that you are rotating for exactly 10 seconds.  Now, do them both together.  From your perspective (as the moon) you ARE rotating, but you'll notice that your face (the Light side of the moon) is always facing the Earth.
218551
It rotates on its axis once per month. If you could stand on the sun, you would see all sides of the moon in the course of a month. Also, if you could stand on Mars you would see all sides of the moon in the course of a month. The "single face" issue arises because we on earth are right in the middle of it--as the moon rotates on its axis once per month, it also revolves about the earth at the same speed, always showing the same face to the earth.\n\nSince the moon does not always show the same face to the sun, there is no "dark" side of the moon. All parts of the moon get equal amounts of sunlight, just as all parts of the earth do. There is a "far" side to the moon, the side that is always facing away from earth.\n\nAnother way to think of it is to think of the flagpole planted by astronauts. It of course is pointed toward the earth at all times. At the time of new moon (when the moon is between the earth and the sun), the flagpole is pointed toward the earth and the outer solar system, toward the realm of Mars, Jupiter, and Saturn. At the time of full moon (when the earth is between the sun and the moon), the flagpole is pointed toward the earth and the sun. Obviously the moon rotated so as to bring the flagpole from pointing to the outer reaches around to pointing toward the sun.\n\n\nFor Dirty Idea (below): ask your question as a Yahoo! question and maybe I'll look it up for you. I think it has to do with tidal locking. It's not a coincidence at all.
313164
Initially?  The Earth and a moon as a system conserve angular momentum.  The events that formed the Earth and the Moon all imparted (or transfered) a angular momentum to the system.  Our mutual rotations about each other are a result of this angular momentum.
1086962
Yes the earth moves round the sun as do the other planets and when the sun and the moon are aligned with the earth then we are eclipsed depending on which part on the planet you live.