"TigerRace1" <tigerrace1@aol.com> wrote in message
news:20041119141045.09660.00000627@mb-m20.aol.com...
Quote:
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There is no dark side of the moon really. As a matter of fact, it's all dark. C.
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Idiot.
Of course, there is a bright side of the Moon, and you can go to it. But if
you sit still, you can only be there for two weeks. The bright side (and
therefore the dark side too) is not a fixed place, but appears to move as
the Moon rotates.
Seen from the surface of the Earth, the Moon does not appear to rotate. This
is because from an outside frame of reference, the Moon rotates once for
every time it goes around the Earth. So from our vantage point, the Moon is
naturally divided into two halves: the hemisphere we always see, called the
nearside, and the hemisphere we do not see, the farside. The farside has
only been seen by probes or astronauts that have actually orbited (or at
least passed by) the Moon.
This is very different from the dark side. As the Moon orbits the Earth,
different parts of it get illuminated by the Sun. When the Moon is between
the Earth and the Sun, we see it almost entirely in shadow. This is called
the new moon. Half a lunar orbit later (two weeks or so) it is fully
illuminated by the Sun, giving us a full moon. In between we get a half
moon, sometimes confusingly called a quarter moon because the Moon has
completed 1/4 of an orbit. These are called the phases of the Moon (I have
heard that some people think that the phases are caused by the shadow of the
Earth on the Moon; but that is whole different can of Bad Astronomy).
So imagine you are standing on a spot directly in the middle of the
nearside. You would see the Earth straight over your head. If it were new
moon to someone on Earth, the Sun would be behind the bulk of the Moon to
you. For you, it would be local midnight! Two weeks later it would be full
moon to someone on Earth, and it would be local noon to you; the Sun would
be high overhead. The half moon to someone on Earth means it would be either
sunrise or sunset to you, depending on whether you are a week past new moon
or a week past full moon, respectively. You can see that the dark side of
the Moon is just simply the night side of the Moon. It is no more a fixed
feature than the night side of the Earth.
The Pink Floyd album may be one of the best selling albums of all time, but
astronomically it's in eclipse.