Effect

Illustration of the moon undergoing phases; first quarter is heading towards a full moon

Illustration of a full moon

Illustration of the moon undergoing phases: last quarter is heading towards a new moon

Illustration of the moon undergoing phases: new moon. The Moon, in its monthly orbital motion around Earth, lies between Earth and the Sun, and is therefore in conjunction with the Sun as seen from Earth. At this time, the dark (unilluminated) portion of the Moon faces almost directly toward Earth, so that the Moon is not visible to the naked eye

Illustration of the moon undergoing phases; waning (decreasing in size) crescent (name of shape), heading towards a new moon

Illustration of the moon undergoing phases; waning (decreasing in size) gibbous (name of shape), heading towards a new moon

Illustration of the moon undergoing phases; waxing (increasing in size) gibbous (name of shape), heading towards a full moon