Hale wrote:
I need to figure out which people have seen mo a lunar or a solar
eclipse. Here is my theory, please tell me if I'm right or wrong (if wrong,
tell me why)
More people have seen a solar eclipse.
Is it because the 5 degree orbit of the moon w/ respect to the
elliptic. There are very few times a year the moon, Earth, and sun are in
perfect alignment that can cause a lunar eclipse, whereas a solar eclipse
does not matter on the alignment of the three celestial bodies. Is this
correct?
No; I think you have it backwards, and *both* solar and lunar
eclipses require a fairly precise alignment, the Moon being at new or
full phase when it's on or very near one of its nodes. Consider the
size difference between the Earth and the Moon: the former casts a
much larger shadow than the latter. During a lunar eclipse, the
Earth's shadow covers the entire lunar disc, and so is visible from
anywhere in the half of the world (generally the 'night side') from
which the Moon can be seen.
Conversely, during a solar eclipse the Moon casts a rather small
shadow on the Earth, and a total eclipse is only visible from a
position right in the shadow. As a solar eclipse progresses the
shadow tracks across the earth's surface. Within this narrow band a
total eclipse is visible (assuming the alignment is good enough --
many eclipses are no better than partial no matter where they're
observed from), from a broader adjacent region to either side it will
appear only partial, and from a certain distance away from this track
it's a 'clean miss'.
The upshot is that although there are about the same number of solar
and lunar eclipses, by and large, in a given period of time, while
about half of the world's population will have an opportunity to see
each lunar eclipse, only a small fraction will see each solar eclipse
-- even counting the 'astro-tourists' who travel long distances to
catch a view.
See
http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html
for all manner of eclipse data and maps to illustrate the above remarks.
FWIW I've never seen a total solar eclipse (although I've seen about
three or four partial ones, up to about 80% obscuration of the solar
disc) but I've seen several total lunar eclipses (and quite a few
partials as well).
--
Odysseus
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