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Partial Lunar Eclipse

June 3, 2012

Earth’s long, dark shadow will take a small “bite” out of the full Moon before sunrise tomorrow. The partial lunar eclipse will be visible across most of the United States, with the best view across the western half of the country.

The eclipse actually begins when the Moon starts to enter the outer portion of the shadow, known as the penumbra. It’s quite faint, though, so most skywatchers won’t notice much of a difference. The Moon will look just slightly fainter than normal, and perhaps a bit yellower.

The most obvious part of the eclipse, known as a partial eclipse, begins when the Moon touches the dark inner part of the shadow — the umbra — at 5 a.m. Central Daylight Time. The shadow will nip at the Moon’s southern edge, engulfing about a third of the Moon’s diameter when the eclipse peaks a little after 6 o’clock. The eclipse ends about an hour later, when the Moon exits the umbra.

From the eastern half of the country, the Moon will set before the eclipse ends. Most of the eclipse will be visible from the Great Plains, with all of it visible from the West Coast, Hawaii, and most of Alaska.

This is the second of three special alignments involving Earth, the Sun, and another astronomical body in about half a month. The first was an annular solar eclipse a couple of weeks ago, and the third is a passage of the planet Venus across the face of the Sun late Tuesday. We’ll have more about that tomorrow.


Script by Damond Benningfield, Copyright 2012


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