Which phase comes after a third quarter moon and before a new moon, with less than half illuminated on the left?

Which phase comes after a third quarter moon and before a new moon, with less than half illuminated on the left?

• A. Waning Crescent
• B. Waxing Crescent
• C. New Moon
• D. First Quarter

Answer: (A)

Understanding how lunar illumination changes over the cycle is key. After the last quarter, the Moon’s illuminated portion continues to shrink and stays on the left, creating a crescent that is less than half-lit. That left-side, diminishing illumination is the signature of the waning crescent phase, which occurs before the New Moon. The other phases don’t fit this description: waxing crescent has a crescent on the right and happens earlier in the cycle, first quarter shows half illumination on the right, and a New Moon is nearly completely dark.

Understanding how lunar illumination changes over the cycle is key. After the last quarter, the Moon’s illuminated portion continues to shrink and stays on the left, creating a crescent that is less than half-lit. That left-side, diminishing illumination is the signature of the waning crescent phase, which occurs before the New Moon. The other phases don’t fit this description: waxing crescent has a crescent on the right and happens earlier in the cycle, first quarter shows half illumination on the right, and a New Moon is nearly completely dark.