where exactly is the moon located?  how far from the earth ?   does the moon go around the earth or the earth go around the moon ?
133590
The moon as you know is orbiting the Earth.  However this does not mean that it is just the Moon going round the Earth.  The Earth also goes around the Moon..... although that isn't strictly true either.\n\nWhat actually happens is that they both orbit about a point which is somewhere inbetween the two, and its position is determined by the mass of each.  It just so happens that as the Earth is so much more massive than the Moon, this point that they both orbit about it actually very very close to the centre of the Earth.
459467
1- yup, Earth\n2 - The sun is about 400 times the diameter of the moon, but is also about 400 times farther away\n3 - Cosmic rays ( a form of electromagnetic energy that would sterilize the surface of our planet within a few months if not blocked ), and meteors, thousands of which would hit us every hour.
297248
Wait, I heard that the moon controlled the length of our days.  When the moon was closer, our days were about 8-9 hours long, the further away the moon gets, the longer our days get (and the moon is reportedly getting further away, slowly)  Now, if it broke up and gave us rings, it's gravity would no longer be concentrated in one spot but all around us, wouldn't that have an effect on our day length?\n\nOoooohh, now I've got a question to add.\nKIM
542258
Are you taking into account the radius of the moon? The equations you've provided treat "r" as the distance between the centers of mass of each object. Therefore:\n\nr = radius of the moon + distance from it's surface\n\nr = 1785 km + 111 km\n\nr = 1,896,000 m\n\nSubstituting this into your equations provides:\n\nT = 2*pi*sqrt((1896000)^3/(6.674x10^-11 * 7.3x10^22))\n\nT = 7431.6 s = 123.9 min\n\nAdditionally:\n\nV = sqrt((6.674x10^-11 * 7.3x10^22) / 1896000)\n\nV = 1603 m/s\n\nHope that clears things up a bit! :)
533625
The moon takes 27.3 days to orbit the Earth.  It also takes exactly the same amount of time to make one full rotation.  So the moon only shows the same side to Earth as it goes round.  This is called 'tidally locked'.
540671
The apogee is the point in the moon's orbit where it is the furthest from Earth; the perigee is it's closest point.
647185
Earth shine is the correct answer. When the Moon is crescent as seen from Earth, the Earth is nearly full as seen from the Moon. And Earth is bigger and has much higher reflectivity than the Moon, so a nearly full Earth gives much more light than a nearly full Moon does.
257499
Moon/Earth Comparison\nBulk parameters\n\n                                   Moon         Earth      Ratio (Moon/Earth)\nMass (1024 kg)                    0.07349       5.9736     0.0123    \nVolume (1010 km3)                 2.1958      108.321      0.0203\nEquatorial radius (km)           1738.1        6378.1    0.2725      \nPolar radius (km)                  1736.0        6356.8    0.2731\nVolumetric mean radius (km)        1737.1        6371.0    0.2727\nEllipticity (Flattening)          0.0012        0.00335    0.36    \nMean density (kg/m3)               3350          5515      0.607      \nSurface gravity (m/s2)            1.62          9.80       0.165    \nSurface acceleration (m/s2)       1.62          9.78       0.166    \nEscape velocity (km/s)            2.38         11.2        0.213    \nGM (x 106 km3/s2)                 0.0049        0.3986     0.0123 \nBond albedo                       0.11          0.306      0.360\nVisual geometric albedo           0.12          0.367      0.330    \nVisual magnitude V(1,0)          +0.21         -3.86          -\nSolar irradiance (W/m2)            1367.6        1367.6    1.000      \nBlack-body temperature (K)          274.5         254.3    1.079      \nTopographic range (km)               16            20      0.800      \nMoment of inertia (I/MR2)         0.394         0.3308     1.191\nJ2 (x 10-6)                     202.7        1082.63        0.187  \nRef The foll link
334494
They actually do, but as previously stated the moon is much less massive than the Earth so we don't rotate as much compared to the moon. \n\nIncidentally: the Moon is not rotating around the Earth in a strict sense, it's actually spiraling away at about one inch per year, eventually the Moon will escape orbit. Just FYI.
287955
The full moon is visible as full anywhere\non earth where it is above the horizon...\nobviously if it is far in the southern\nhemisphere and you are far north, like\nin northern Finland, you may not see the\nfull moon at all... (but if you could it\nwould still appear full)
3856
I'm not sure about the distance to the moon, but I can explain the rest...\n\nLots of questions here... \n\nFirst, they found out about the curvature of the earth mainly by observing the earth's shadow on the moon during a lunar eclipse. You can easily see the Earth's shadow as curved and not straight.\n\nThe experiment with the sticks, performed by Eratosthenes, was to determine the circumference of the earth, and thus, how big it is.\n\nYou're absolutely right with the argument that the shade produced by a stick on a flat surface would be different than that on a curved surface.\n\nEratosthenes went with the [correct] assumption that the sun was so far away, that its light rays striking the earth would be parallel to each other.\n\nIn truth, this only occurs for an object that is infinitely far away, but the sun is SO far away, that this difference, from two different places on Earth, is negligable.\n\nSo if you have a flat surface, then no matter where you are on the surface, the shadow cast by a stick should be the same. If its noon, and the light rights are parallel, and the Earth is flat, then there should be no shadow no matter where you are on the surface.\n\nNow, Eratosthenes saw that at noon, in two different cities, that in one city, there was no shadow cast by the stick, meaning the sun was directly overhead, and at the same time in the other city, there was a small shadow, and measured the angle the stick made with the shadow. \n\nHe noticed the angle was about 7 degrees, which means its 1/50th of a full circle (360 degrees). Therefore, the two cities were 1/50th the way around the globe. Knowing how far the cities were, he multiplied their distance by 50 and got the distance around the globe. c = 2*pi*r, so he could then calculate the radius of the earth as well!\n\nThat's pretty much it, hoped you understood it. Its really amazing how they could get the size of the earth simply by using two old sticks and a little thought! :)
143680
As others mentioned, the moon has no atmosphere of its own for weather patterns to develop. \n\nThe only wind the moon (or Earth) experiences is the Solar wind.  The solar wind consists of highly energy ions in the form of a plasma.  While the solar wind can effect radio signals and such, it isn't going to do anything to Neil Armstrong's footprints.\n\nThe only thing that truly disturbs the moon surface is impacts by meteorites.  This is evident by the many craters we can see.
62084
300 million years ago the day was about 22 hrs long. Earths rotation is getting slower and the days will be getting longer. This is because of the tidal forces between the earth and the moon. Earths oceans are being pulled on by the moons gravity. But as the moon moves in its orbit the oceans cant follow in a nice bulge because of the continents. So the oceans form another gravitaional centre offset from the center of the earth. This out-of sync tug is whats making the moon move farther away from the earth. The same force is slowing the earhts rotation. The moon is moving away from the earth by a couple of cms/year. How much longer the day gets each year I cant remember. It´s in the neighbourhood of nanoseconds. A leap second was acutally added to 2005.
482101
Mathematically, on the moon you could now throw the ball 240m.\n\nScientifically, on the moon you could throw the ball 240m and farther. On the moon, their is only gravity bringing the ball to a stop. On Earth, gravity and friction of the air slows the ball down
515771
The Moon is spherical, so of course half of it's hidden all the time. The Moon's in a tidally locked orbit as well, so the same face is always towards Earth; 44 percent of the Moon's surface can never be seen from Earth.\n\nBut I don't think that's what you were asking. I think you were asking why the Moon looks like a sliver. It's also simple: the Moon is lit by sunlight. You will notice the bright part of the Moon ALWAYS, without exception, points at the Sun. (Sometimes you can faintly see the side away from the Sun; this faint illumination is sunlight bouncing off Earth's clouds and feebly illuminating the Moon through radiosity.)\n\nTo demonstrate the phases of the moon, get a ball and a lamp in a darkened room. Hold up the ball in front of you and turn around. Notice the phases of the ball, just like the Moon.
249625
The Moon's mass is less but you're closer to the centre.   Gravity goes up as the square of your distance from the centre.
140494
what? I don't think the moon appears stationary since it travels across the sky and goes through phases.\nWhat?