Quick Summary
A black moon is a rare type of new moon, either the second in a month or the third in a season with four. On August 23, 2025, we’ll see a seasonal black moon, which happens only once every 33 months.
You won’t see the moon itself, but you’ll get something better: one of the darkest, clearest nights of the year for stargazing. Look for the Milky Way stretching across the Summer Triangle, and take advantage of the rare chance to enjoy the night sky at its best.
One of the best stargazing nights of the year
At 2:06 a.m. EDT on Saturday, August 23, the moon will officially slip into its new moon phase. That’s not unusual; it happens every 29.5 days. What is unusual is that this particular new moon has a special title: a “black moon.”
You won’t actually see the moon in the night sky, new moons are invisible because the moon passes between Earth and the sun. But this blackout on the lunar calendar creates a window for one of the best stargazing nights of the year.
So, what exactly is a black moon, and why does it matter for skywatchers?
What is a black moon?
Astronomers and skywatchers use the term “black moon” in two different ways:
- Monthly black moon: The second new moon in a single calendar month. This happens about once every 29 months. The next one will occur on August 31, 2027.
- Seasonal black moon: The third new moon in a season that has four new moons. This happens only once every 33 months.
The August 23 event is a seasonal black moon. This summer squeezed in four new moons — June 25, July 24, August 23, and September 21 — because the first fell just days after the solstice. That rare calendar quirk makes Saturday’s new moon the third of the season, earning it the “black” label.
Why is a black moon important for stargazing?
While the moon itself won’t be visible, its absence is exactly what excites astronomers and casual stargazers alike. A moonless sky means less natural light pollution, which creates ideal conditions for spotting:
- The Milky Way: From the Northern Hemisphere, the bright river of our galaxy will be at its peak visibility in August nights.
- The Summer Triangle: Look southeast for Vega, Deneb, and Altair, three bright stars forming an easy-to-spot triangle. The Milky Way streams right through it.
- Fainter constellations and star clusters: Without moonlight, you’ll see stars and deep-sky objects that are usually drowned out.
This particular black moon arrives during late summer, when the Milky Way arches high overhead. That combination makes it one of the best skywatching weekends of 2025.
How rare is the black moon?
To put things in perspective:
- A blue moon — the second full moon in a month, occurs about once every 2–3 years.
- A monthly black moon is on the same schedule: once every 29 months.
- A seasonal black moon is even rarer, happening just once every 33 months.
In other words, if you miss this one, you’ll be waiting nearly three years for the next.
How to make the most of the black moon night
You won’t see the black moon itself, but you can plan for some of the best starry skies of the year:
- Get away from city lights: The darker the horizon, the more you’ll see. Rural areas or national parks are perfect.
- Look south: The Milky Way runs along the southern sky this time of year.
- Bring binoculars or a telescope: They’ll reveal detail in star clusters like the Pleiades or the Andromeda Galaxy.
- Check local conditions: Cloud cover can ruin the view. Apps like Clear Outside or local observatories’ forecasts can help.
- Give your eyes time to adjust: Spend at least 20 minutes in darkness to maximize visibility.
Why do astronomers care about naming these moons?
Lunar naming traditions have always been part science, part culture. While “harvest moon” and “hunter’s moon” come from farming cycles, terms like “blue moon” and “black moon” are more modern quirks of the calendar.
But they matter because they spark public interest in astronomy. Events like a black moon get people outside, looking up, and engaging with the night sky — often leading to deeper curiosity about space science.
For astronomers, the practical benefit is simple: new moons, and especially black moons, offer the darkest skies available. That’s prime time for studying faint celestial objects, photographing the Milky Way, or hunting for meteors.
When is the next black moon?
- Monthly black moon: August 31, 2027.
- Seasonal black moon: May 19, 2028.
So, while they aren’t once-in-a-lifetime events, they’re rare enough that it’s worth marking your calendar.