The Moon’s phases, from new to full and back

What changes in the sky

The Moon reflects sunlight. As it orbits Earth, our view of its sunlit half changes, producing the phases. The new-to-new cycle takes about 29.5 days. A normal lunar phase is not caused by Earth’s shadow; that explanation belongs to a lunar eclipse.

A simple sequence

The familiar sequence is new Moon, waxing crescent, first quarter, waxing gibbous, full Moon, waning gibbous, third quarter and waning crescent. Waxing means the illuminated portion we see is increasing; waning means it is decreasing. The exact quarter and full phases are instants, even though the Moon looks similar on neighboring nights.

An optional personal rhythm

Some people use a new Moon to choose an intention and a full Moon to review it. That is a symbolic practice, not evidence that a phase causes personal events. You can enjoy the rhythm while choosing actions according to your own needs and circumstances.

Further reading

• NASA: Moon phases ↗