Why do solar and lunar eclipses not occur every month?

Solar and lunar eclipses do not occur every month because the Moon’s orbital plane is inclined by approximately 5° relative to the ecliptic, which is the plane of Earth’s orbit around the Sun.12

Because of this tilt, the Moon typically passes above or below the Sun during a new moon (when solar eclipses would otherwise occur) and above or below Earth's shadow during a full moon (when lunar eclipses would otherwise occur). Consequently, the Sun, Earth, and Moon are rarely aligned in a straight line.132

For an eclipse to occur, the Moon must be near a node—the specific points where the Moon’s orbital path crosses the ecliptic. These alignments happen only during "eclipse seasons," which occur roughly every six months when the Sun is near one of these nodes.134