What is a “Waning Crescent Moon”?

26 June 2014 

The Short Answer (TSA)

A Crescent Moon is one phase in the regular cycle of the phases of the Moon.  The Moon is in the “Crescent” phase whenever part, but less than half, of the Moon’s face is sunlit.  “Waning” means getting smaller.  So, the Moon is called a “Waning Crescent Moon” when the sunlit part of the face of the Moon is (1) getting smaller and (2) appears in the shape of crescent.

Waning Crescent Moon (Northern Hemisphere)

The Moon’s phases begin with the “New Moon” when the Moon disappears from the night sky.  The next phase is called the “Waxing Crescent Moon.”  The Moon reappears, but the sunlit part of its face is only a tiny sliver in shape of a crescent.  This first “Crescent Moon” continues to “wax” until it reaches the next phase, the “1st Quarter.”

Moon's Phases (Northern Hemisphere)

The “Waning Crescent Moon” comes at the end of the cycle of phases. The sunlit part of the Moon’s face “wanes” (or gets smaller) after the “Full Moon” until only half the Moon’s face is sunlit at the phase called the “3rd Quarter.”

As soon as less than one half (1/2) of the Moon’s face is sunlit, the “Waning Crescent Moon” begins. With each passing night the crescent of light gets smaller and smaller until all the light disappears at the next phase, the “New Moon.”  With the “New Moon” the cycle of phases begins again.