The Moon does not make its own light; it reflects 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 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
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