Moon Phases

What is a waning gibbous moon?

Posted by

and

January 1, 2023

Waning gibbous moon

Between full and last quarter moon – late at night or in the early morning – you might catch the moon in its waning gibbous phase. It’ll appear less than full but more than half-lighted. A full moon rises just at sunset. But a waning gibbous moon rises later at night than a full moon. You’ll catch it ascending over your eastern horizon somewhere between your local sundown and midnight.

A waning gibbous moon can surprise you if you happen to be out late in the evening and you catch it rising eerily, some hours after sunset. It’ll be glowing red like a misshapen full moon when it’s near the horizon.

View at EarthSky Community Photos. | Lorraine Boyd in Delmar, New York, captured this photo of the moon in the waning gibbous phase on October 28, 2021. She wrote: “The moon in the waning gibbous phase (about 58% illumination), approaching the last quarter phase.” Thank you, Lorraine!

Sometimes you’ll notice it in the daytime sky

A waning gibbous moon also initiates a rash of questions about seeing the moon during the day.

If it rises late at night, you know the waning gibbous moon must set after sunrise.

Yes, the moon is up in the daytime for half of every month. It’s just not as obvious then because a daylight moon is so pale, and the sun is so bright. So, if the moon is close to the sun, bright sunlight will drown it from view. Watch for the daylight moon in the west in the days following a full moon. You’ll see it in early morning, floating like a pale ghost against the blue sky.

Moon, Mars, ducks flying in a V. — View at EarthSky Community Photos. | Peter Lowenstein in Mutare, Zimbabwe caught the waning moon, Mars, and a flock of whistling ducks at dawn on August 9, 2020. He wrote, “… the waning gibbous moon and Mars were close together high in the northern dawn sky. Several pictures of the pair were taken as daylight approached between 6 and 6:30 a.m. Just before it became too light for Mars to remain visible, a flock of whistling ducks passed by in bow and arrow formation!” Thank you, Peter!

Bulging white moon in blue sky over orange-red flowers. — View at EarthSky Community Photos. | Peter Lowenstein caught the early morning waning gibbous moon from Mutare, Zimbabwe, on May 11, 2020. He said: “Three quarters of an hour after sunrise the daytime waning gibbous moon was photographed descending towards the top of a flowering African tulip (*Spathodia campanulta*) tree on Murambi Heights.”

Understanding moon phases

As the moon orbits Earth, it changes phase in an orderly way. Follow the links below to understand the phases of the moon.

New moon
Waxing crescent moon
First quarter moon
Waxing gibbous moon
Full moon
Waning gibbous moon
Last quarter moon
Waning crescent moon

Bottom line: See the waning gibbous moon between the full and last quarter phases. It’s best viewed from late night through early morning.

Help EarthSky keep going! Please donate

Posted

January 1, 2023

in

Moon Phases

Deborah Byrd

View Articles

About the Author:

Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. In 2020, she won the Education Prize from the American Astronomical Society, the largest organization of professional astronomers in North America. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.