The first quarter moon is a phase of the moon that occurs when the moon is approximately one-quarter of the way through its cycle from new moon to full moon. It appears as a half-circle, with the illuminated portion facing towards the east.

Here are some key characteristics of the first quarter moon:

* Appearance: Half-illuminated, shaped like a crescent with the curved edge facing east.

* Position in the sky: Visible in the afternoon and evening, highest in the sky around midnight.

* Lunar phase: One-quarter of the way through the lunar cycle.

* Timing: Approximately 7 days after the new moon.

The first quarter moon is often referred to as a waxing gibbous moon, meaning that the illuminated portion is increasing in size.