The moon is gradually becoming dimmer each night following the full moon. What is the reason for this? It pertains to the lunar cycle.

The lunar cycle is made up of eight unique stages of the moon’s visibility. This complete cycle spans approximately 29.5 days, as stated by NASA, and these stages take place as the Sun shines on various sections of the moon during its orbit around Earth.

So, what is occurring with the moon this evening, Aug. 11?

What is the moon phase today?

On Monday, Aug. 11, the moon phase is Waning Gibbous, and it is 94% illuminated from our perspective on Earth, according to NASA’s Daily Moon Observation.

Without any visual equipment, tonight you can observe the Aristarchus Plateau, the Mare Vaporum, and the Mare Serenitatis. Binoculars will provide even more detail, revealing the Gassendi Crater and Mare Frigoris. With a telescope, Apollo 15, the Schiller Crater, and more will come into view.

When is the next full moon?

The upcoming full moon will occur on Sept. 7. The previous full moon was on Aug. 9.

What are moon phases?

As per NASA, moon phases arise from the 29.5-day orbit of the moon, which modifies the angles among the Sun, Moon, and Earth. Moon phases show how the moon appears from Earth as it circles around us. We consistently see the same side of the moon, but the proportion illuminated by the Sun varies based on its orbital position. This leads to full moons, half moons, and moons that seem entirely invisible. There are eight primary moon phases, which follow a cyclic pattern:

New Moon – The moon is located between Earth and the sun, resulting in the side we observe being dark (essentially, it’s not visible).

Waxing Crescent – A small slice of light emerges on the right side (Northern Hemisphere).

First Quarter – The right side of the moon is illuminated halfway. It looks like a half-moon.

Waxing Gibbous – More than half is lit, but it isn’t quite full yet.

Full Moon – The entire face of the moon is radiantly lit and fully observable.

Waning Gibbous – The moon begins to lose illumination on the right side.

Last Quarter (or Third Quarter) – Another half-moon, but now the left side is lit.

Waning Crescent – A narrow slice of light stays on the left side before disappearing into darkness again.