Moon Phases
- The Moon does not make its own light; it reflects the light from the Sun.
- The Sun continuously illuminates half of the Moon’s surface, but varying amounts of it are visible from Earth at any moment.
- Changes in visibility of the Moon’s surface follow a predictable pattern called the lunar cycle.
- The positions of the Sun, Earth, and Moon as they move through space cause the lunar phases to occur to viewers from Earth.
- The Moon revolves around the Earth about every 28 days.
- The lunar phases occur in order: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent.
- The lunar phases change about every 3.5 days.
- Waxing
- waning
- crescent
- gibbous
- revolution
Gibbous: A gibbous moon is one of the phases of the Moon, when the size of the illuminated portion is greater than half but not a full Moon. The period between a first quarter moon and a full moon is known as a waxing gibbous moon, because the illuminated region of the Moon is increasing from day to day.