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Moonless Nights

September 16, 2012

Several brilliant stars are in good view as night falls this evening. Yellow-orange Arcturus is in the west, with reddish-orange Antares, the heart of the scorpion, low in the southwest. And the stars of the Summer Triangle — Vega, Deneb, and Altair — stand high overhead.

Many other stars are in good view as well, thanks to the Moon — or to be more specific, the Moon’s absence.

The Moon was “new” on Saturday night, when it crossed the line between Earth and Sun. So as night falls this evening, the Moon is roughly 24 hours old — 24 hours past new. It’s too close to the Sun to find without optical aid. And even if you could find it, it’s nighttime across almost the entire lunar hemisphere that faces our way — only a tiny edge of it is bathed in sunlight.

Moonless nights are some of the best for skywatching. As the Moon grows fatter, it casts more light into the sky, overpowering the glow of the stars. It also overpowers meteors, which are some of the night sky’s most ooh-inspiring sights.

To fully appreciate those sights, you have to get away from an even peskier glow — city lights. They fill the sky with such a haze that the stars all but disappear.

If you’re a fan of the Moon, though, you won’t have long to wait for it to return to view. It’ll be quite low in the southwest as darkness begins to fall tomorrow night — a thin crescent that’s easy to see, but that’s not yet exerting its dominance over the night sky.


Script by Damond Benningfield, Copyright 2012

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