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To: the_devils_advocate_666

Thanks for the map. Please explain the meanings or P1, U1, U4, and P4.


12 posted on 06/25/2010 2:52:18 PM PDT by justiceseeker93
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To: justiceseeker93
P stands for penumbra and U for umbra. If you were on the moon, the penumbral phase would mean that the sun was partly hidden by the earth. The umbral phase would mean the sun was completely hidden by the earth.

For earth-bound observers, the penumbral stage is not very striking--the moon's surface should be somewhat darker than normal but you're seeing a part of the moon that is still getting some sunlight. The umbral phase is darker and more noticeable.

From the map, it looks like the moon sets over Chicago shortly after the start of the umbral stage, so it may not be worth getting up early for. Even in the Pacific time zone, the eclipse will be partial--the earth's shadow will be noticeable but won't cover the entire earth-facing surface of the moon.

Two weeks from now (July 11) there will be total eclipse of the sun, but the path of totality goes mostly over the south Pacific--totality will be visible from Easter Island and from some remote parts of southern Chile and southern Argentina (assuming the skies are clear).

18 posted on 06/25/2010 4:28:30 PM PDT by Verginius Rufus
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To: justiceseeker93
Please explain the meanings or P1, U1, U4, and P4.

You sank my battleship???

23 posted on 06/25/2010 8:32:25 PM PDT by mountn man (The pleasure you get from life, is equal to the attitude you put into it.)
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