Phases of the Moon

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Animation of the moon phases

The phases of the moon are the different ways the Moon looks from Earth during a month. Each lunar phase can be identified by the appearance of the moon and the time of the month. As the Moon moves in space, different parts of it face the Sun. This means that different parts of it are lit up. We only see one side of the moon from Earth because it rotates so that one side is always facing us. The same phases happen again and again, every 29.5 days, approximately. The phases of the moon appears to be a circular disk, which is illuminated to some degree by direct sunlight.

Moon changes[change | edit source]

Waning Moon
  • Waxing is when the part of the moon that we can see gets bigger every night. It waxes until it is a full moon.
  • Waning is when the moon appears to be getting smaller in size every night. It wanes until it is a new moon.

Phases[change | edit source]

There are 8 total phases that the moon goes through.

  • The new moon is when the moon is all dark. None of the moon that we can see is lit up during the new moon. This starts the cycle, and is a kind of conjunction.
  • A crescent moon is when the moon is between the new and quarter moon stages. It looks like a "C" shape.
  • The quarter moon (or a half moon) is when half of the moon is visible. If the moon is waxing, it is called the first quarter, if the moon is waning, it is the last quarter
  • A gibbous moon is between the quarter and full moon stages. More than half of the moon can be seen, but not all of it.
  • The full moon is when the moon is all lit up. All of the moon that we can see is lit up by the Sun during the full moon.
    • A second full moon in one calendar month is usually called a blue moon. The saying "Once in a blue moon" refers to something that does not happen often - like a blue moon.[1][2]

References[change | edit source]

  1. However, a blue moon can also refer to the third full moon in a season with four full moons.
  2. Sinnott, Roger W., Donald W. Olson, and Richard Tresch Fienberg (May 1999). "What's a Blue Moon?". Sky & Telescope. http://www.skyandtelescope.com/observing/objects/moon/3304131.html?showAll=y&c=y. Retrieved 2008-02-09. "The trendy definition of "blue Moon" as the second full Moon in a month is a mistake."