First Quarter
Next occurrence (UTC):
Typical illumination: 50%
At first quarter the Moon has completed about one quarter of its orbit since new moon. We see roughly half of the disk lit — the right half in the Northern Hemisphere.
How it looks
The terminator (day–night line) runs nearly north–south across the disk, casting sharp shadows in craters along the edge. It is an excellent phase for telescopic observing.
When it is visible
First quarter rises around midday, is high in the afternoon and evening sky, and sets around midnight. It is the classic early-evening half moon.
Geometry
Phase longitude is near 90°. The Moon–Earth–Sun angle is about a right angle, so half the Earth-facing hemisphere is sunlit.