Phases of the Moon Features

Full Moon

• The full moon occurs when the moon is at a position in its orbit where the Earth is between the moon and the sun, illuminating the side of the moon that faces the sun.

  Only during the full moon is the entire surface of the moon able to be seen from Earth. Before artificial lighting, this phase of the moon was of particular importance because it enabled individuals to extend the day's activity with the bright moonlight. September's full moon is usually celebrated as the Harvest Moon, because it allows farmers to work into the night harvesting crops and preparing for the winter. The full moon is also associated with legends of werewolves and a rise in unexplained behavior from humans and animals.

Gibbous Moon

• The gibbous moon occurs both before and after the full moon. In the days leading up to the full moon, the amount visible from the Earth's surface is slowly increasing and it is known as the waxing gibbous. After the full moon, the amount visible is slowly decreasing, giving it the name of the waning gibbous. In both cases, more than half of the moon is visible. In the moon's cycle, two weeks of it is spent in a gibbous phase.

Half Moon

• The half moon occurs twice in the cycle: once between the full moon and new moon, and once as the orbit goes the other way toward the full moon. At the half moon phase, the moon is positioned at a right angle to the Earth in regards to the sun. Exactly half of the moon is seen to be illuminated, always the side toward the sun. The second half moon of the cycle will appear to be the mirror image of the first.

  This moon is also called the quarter moon. Half describes the amount of the body that is illuminated, while quarter describes the point in the moon's cycle that it occurs in.

Crescent Moon

• The crescent moon occurs both before and after the new moon. Less than half is visible from Earth, and when it is nearing the new moon it is called the waning crescent. After the new moon, the phase is referred to as the waxing crescent.

New Moon

• The new moon occurs when the moon is directly between the Earth and the sun, and the far side of the moon is illuminated. It is typically not visible in the night sky, leaving the only natural illumination to be the stars. In the lunar cycle, it occurs directly opposite the full moon and between the two half moons.