| A | B |
|---|
| New Moon | The moon is not visible in the sky. Except during a solar eclipse,  |
| Waxing Crescent | The moon is less than one-half illuminated by the sun but less than one quarter illuminated. Occurs when the moon's illumination is increasing,  |
| First Quarter | The moon is one-half illuminated by the sun. Occurs when the moon's illumination is increasing,  |
| Waxing Gibbous | The moon is more than one-half illuminated by the sun but not completely illuminated. Occurs when the moon's illumination is increasing,  |
| Full Moon | The moon is totally visible in the sky. Except during a lunar eclipse,  |
| Waning Gibbous | The moon is more than one-half illuminated by the sun but not completely illuminated. Occurs when the moon's illumination is decreasing,  |
| Third Quarter | The moon is one-half illuminated by the sun. Occurs when the moon's illumination is decreasing,  |
| Waning Crescent | The moon is less than one-half illuminated by the sun but less than one quarter illuminated. Occurs when the moon's illumination is decreasing,  |
