EarthSky // Tonight // Moon Phases By Deborah Byrd May 15, 2012

Understanding waning crescent moon

A waning crescent moon is sometimes called an old moon. It’s seen in the east before dawn.

A waning crescent moon is sometimes called an old moon. It’s seen in the east before dawn.

Now the moon has moved nearly entirely around in its orbit of Earth, as measured from one new moon to the next.

Photo Credit: Brunk Ford Braun

Because the moon is nearly on a line with the Earth and sun again, the day hemisphere of the moon is facing mostly away from us once more. We see only a slender fraction of the moon’s day side: a crescent moon.

Each morning before dawn, because the moon is moving eastward in orbit around Earth, the moon appears closer to the sunrise glare. We see less and less of the moon’s day side, and thus the crescent in the east before dawn appears thinner each day.

The moon, as always, is rising in the east day after day. But most people won’t see this moon phase unless they get up early. When the sun comes up, and the sky grows brighter, the waning crescent moon fades. Now the moon is so near the Earth/sun line that the sun’s glare is drowning this slim moon from view.

Still, the waning crescent is up there, nearly all day long, moving ahead of the sun across the sky’s dome. It sets in the west several hours or less before sunset.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Understanding Moon Phases
Waxing Crescent
First Quarter
Waxing Gibbous
Full Moon
Waning Gibbous
Last Quarter
Waning Crescent
New Moon

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26 Responses to Understanding waning crescent moon

  1. laurel says:

    this website is like the only place i have looked and i got tons of info :)

  2. xdcfghjhgtgbn says:

    booooooooooooooooooooo

  3. sarah says:

    i no why did u do that anyway i mean what did the moon ever do to you?

  4. Fairley says:

    I even now have belief the fact that most of The states was not that moronic to vote for Obama.

  5. Richie says:

    I thought that “crescent” had something to do with “crescendo’ and “increase”, all about getting larger. So how do we get a waning crescent moon?

    • bullwinkle says:

      I thought crescent meant “any shape resembling the curved shape of the moon in its first or last quarters” when part of a circle is cut out of the circle.

      • EarthSky says:

        Well, not exactly. A crescent moon is thinner – smaller in phase – than a first or last quarter moon.

        At first or last quarter, the line between the moon’s light and dark skies (called the “terminator”) is straight.

        In the crescent phase, the terminator line appears concave – curving inward in the direciton of the lighted portion.

    • EarthSky says:

      Richie … I suspect the names have just evolved through time, as ordinary folks have seen the moon and talked about it. Language is sometimes not as precise as we might wish.

      Clear skies!

      ES

  6. Bob says:

    I think this sight is a good source of information, and i got a lot out of it. Thank you for helping me through Grade 6 science!

  7. chip hall says:

    Why no mention of misletoe and oak cerimony. waxing crescent moon sixth day provides perfect health and healing.
    Chip, rub dirt on it
    christian Scientist.

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  10. luce says:

    es muy bueno por que aprende mos muchoooooooooo las formas de la luna gracia a nustros ante pasados

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  18. miguel says:

    our subject science- will enjoying about the phases and other object in the earth because it so nice…… :))

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