In the week following last quarter moon, the moon continues to wane. You’ll see it as a waning crescent moon – sometimes called an old moon – visible in the east before dawn.
Each morning, the moon shows us less and less of its lighted side. It rises closer to the sunrise, heading for new moon.
Many people miss the waning crescent moon because it’s a morning moon, visible before sunrise. But it’s fun to follow the waning crescent day by day, as it inches into the dawn glare.
Autumn is a wonderful time to see a waning crescent moon because – as dawn breaks on autumn mornings – the ecliptic stands nearly straight up with respect to the sunrise horizon. The ecliptic is the path of the sun, moon and planets. When its angle is perpendicular to the horizon, the moon is above the sunrise, rather than to one side of it, and hence easier to see.
As the moon orbits Earth, it changes phase in an orderly way. Follow the links below to understand the phases of the moon.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. 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. 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.