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|MOON OVER THE HEMISPHERES
PICTURE AT THE TOP OF THE PAGE: Strictly speaking, the above picture applies to anyplace in the
southern hemisphere as compared with the northeren hemisphere. In fact, it can't apply exactly to
Antarctica, because you can't even see the Big Dipper that far south. The earth is in the way. But it is
still true that anything you look at, astronomically speaking, will seem upside down in one of the hemispheres
as compared to the other. I took a few pictures of the moon to check that out.
|** I know the moon doesn't roll around on the surface of the earth. It is in an orbit which in turn is in a plane that passes through
the center of the earth at a fairly small angle to the earth's equator. That still makes you look roughly toward the equator to see
it when it is midway between rising and setting.
* OK, I admit to messing with these. Sorry, I can't help it. I zoomed on the moon with the camera and then increased the zoom in
the computer. And then I added a horizon -- a different one in each case. The southern hemisphere pictures have an ocean
foreground, and the northern hemisphere ones have a cityscape.
But, and here is the point of this page, I did NOT rotate the moon. In these pictures, the moon has the same orientation with the
horizon as it did in real life.
I snapped this full moon picture on Jan 10, 2009, on the
MS Amsterdam between Montevideo and the Falkland
Islands. I zoomed in on it a bit (see below *) and
thought it was somehow out of kilter.
Of course, one reason for that is that it was fairly low
in the north. If you are a northern hemisphere dweller
like me, you never saw it there.
I took this picture, again of a full moon, from my
backyard after the trip on March 12, 2009. This time
it was south of me.
The moon orbits around the earth roughly, though not
exactly, between the earth's two hemispheres.** So
you have to look in the general direction of the equator
to see it. That is naturally not true when it is rising or
setting, but when it is around midway between you need
to look south if you are in the north and north if you are
in the south.
Take a look at those dark features on the moon and at how they are twisted around in one picture
relative to the other one. You could make it look rotated like that by twisting yourself around so that
your head is pointed in another direction. And you can rotate yourself that way by moving from one
hemisphere to another.
Now here is the moon just past the first quarter
phase. I took this picture on January 6, 2009
after a night and most of a day of sailing south
from Rio. It was still daylight. See that dark
feature on the upper left of the moon that I think
looks like a claw, or maybe the partially open
mouth of a dragon. (I am strange. I see these
things on the moon instead of a "man in the moon".
Well, there is that same feature, rotated all the
way around, in the bottom picture. I took this
one from my northern hemisphere back yard
after the trip on March 5, 2009. I also stuck a
Chicago scene*** into the picture for a horizon,
but I didn't rotate the picture of the moon.
You can't reliably compare the exact rotation of
one lunar image relative to the other without
taking the time of day into account, which I
didn't do. But you can still see that this feature
(the "claw" as I - possibly alone in the world -
call it) on the moon seem to be generally on the
left in the southern hemisphere and generally on
the right in the north.
*** And if you know Chicago, you know that isn't looking south. But I actually took the picture of the moon in my Clinton, IA
backyard, and it was south of me. I took that Chicago picture the previous summer, and I thought they looked good together. So
The directions are generally right in the other three pictures, although there is no way to verify that other than my memory.
WHAT IS THIS "CLAW"?
Here it is. I guess I am strange, but I can never see a "man
in the moon". Sometimes, though, I see a lobster there with
a claw. This claw is really several of the so-called "seas" on
the moon, named in the picture to the left. They are not
really made of water, though. They are dark flows of lava
into extra large craters early in the moon's lifetime.
However, the brighter, crater ridden areas, called highlands,
are older. The Sea of Tranquility is the site of the first
landing of humans on the moon, Apollo 11, on July 20, 1969.