Waning and waxing

The idea

Over about two weeks the Moon's bright portion shrinks from full Moon to new Moon (the waning period), then grows back to full Moon (the waxing period); the cycle from one full Moon to the next takes about a month.

A fortnight

The bright part of the Moon shrinks for about two weeks until it cannot be seen. Then it grows again.

What are the two periods called?

• Waning and waxing
• Rising and setting
• Summer and winter

Follow the cycle

Start at the full Moon. Go through the half Moon of the waning period, the new Moon, and the half Moon of the waxing period.

A cycle of about a month

From full Moon to a half circle takes about a week. Another week brings it to new Moon. This two-week period is waning. Then the bright side grows to a half circle and then to a full circle in another two weeks. This is waxing. One cycle from full Moon to the next takes about a month.

Waning: bright part shrinks (full Moon to new Moon, about 2 weeks). Waxing: bright part grows (new Moon to full Moon). One cycle takes about a month. In India: waning = Krishna Paksha, waxing = Shukla Paksha.

Notes

Waning = shrinking (Krishna Paksha). Waxing = growing (Shukla Paksha). A full cycle is about a month.

Check yourself

The period in which the bright part of the Moon shrinks is …

The period in which the bright part of the Moon grows is …

In India the waxing period is generally called …

The cycle from one full Moon to the next takes about …

• waxing. Waxing is when the bright part grows.
• full. Waning is when the bright part shrinks.
• waning — correct. Yes!
• waxing — correct. Yes!
• waning. Waning is when the bright part shrinks.
• new. Waxing is when the bright part grows.
• Krishna Paksha. Krishna Paksha is the waning period.
• Shukla Paksha — correct. Yes!
• Amavasya. Amavasya is the new Moon day.
• a day. The cycle takes about a month.
• a year. The cycle takes about a month.
• a month — correct. Yes!