The Moon ‘waxes’ during the phase from New Moon to Full Moon – the illuminated area increases in size every day. The Moon ‘wanes’ during the phase between the Full Moon and the next New Moon. Every night the illuminated area becomes smaller. … when you can draw a ‘d’ then the Moon is waning, (d as decreasing).

What causes the Moon to wax?

When the Moon is in between the Earth and the Sun, the side of the Moon facing away from the Earth is fully illuminated, and the side we can see is shrouded in darkness. As the Moon orbits the Earth, the angle between the Moon and the Sun increases. This is what astronomers call a waxing moon.

What does it mean when the Moon starts to wane?

The moon is called a waning moon when it is in the phase in which its visible surface area is getting smaller. A waning moon occurs between a full moon (when the visible surface is fully round and lit up) and a new moon (when the surface that faces Earth is completely covered in shadow).

Increase and decrease, as in size, number, strength, or intensity, as in Enrollments in these programs wax and wane from year to year. This expression alludes to the phases of the moon, with its periodic changes in size. It was first recorded in the 1300s.