First Quarter
Exactly half of the Moon's visible surface is illuminated — the right half in the Northern Hemisphere. Despite being called a 'quarter,' half the Moon is lit because we're one quarter of the way through the lunar cycle. The Moon rises around noon and sets around midnight.
Orbital Geometry
The Moon is at a 90° angle from the Sun as seen from Earth (eastern quadrature). Exactly half of the near side is illuminated. Despite being called a 'quarter,' we see half the Moon lit because the term refers to the lunar cycle position.
Visibility & Observation
The Moon rises around noon, reaches its highest point at sunset, and sets around midnight. The terminator (day-night boundary) appears perfectly straight, revealing dramatic crater shadows.
Tidal Effects
This phase produces neap tides — moderate tides — because the Sun and Moon are at right angles to each other, partially canceling their gravitational effects.