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Short Moon

June 26, 2010

The Moon makes itself scarce tonight. It was "full" early today, so it rises not long after sunset and remains in view for the rest of the night. But since the night is short, so is the time for moonwatching.

The length of time that the full Moon is in view varies by season and by latitude. At the equator, the full Moon is always in view for about 12 hours. As you move farther from the equator, though, there's a bigger difference based on the time of year.

That's because Earth is tilted on its axis. At this time of year -- the start of summer in the northern hemisphere -- the north pole dips sunward. So during the day, the Sun sails high overhead for northern latitudes, and it stays in view for a long time -- up to about 16 hours as seen from the Lower 48 States, and up to 20 hours or more from parts of Alaska.

But the full Moon always does just the opposite of what the Sun does. So if the Sun is high in the sky and in view for a long time, then the Moon is low in the sky and in view for only a little while. Saint Louis, for example, will see less than 10 hours of moonlight tonight, while Seattle will see less than nine. And that's actually a few minutes more moonlight than last night, because the Moon reached "full" around the time it was setting early this morning.

So wherever you are, enjoy the warm summer evening and the beautiful moonlight -- but do it in a hurry.

Tomorrow: a string of celestial jewels.

Script by Damond Benningfield, Copyright 2010

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