What Is a Supermoon, and When Is the Next One?
Every few months, headlines announce a "supermoon." Some photos make it look enormous, hanging over a city skyline. Then people step outside and see what looks like an ordinary full Moon. Both reactions make sense once you know what a supermoon actually is, and what it is not.
Everything below comes from NASA's own Moon pages.
1. The short definition
NASA explains that the Moon's orbit is not a perfect circle. Sometimes the Moon is a little closer to Earth and appears slightly larger; sometimes it is a little farther away and appears slightly smaller.
A supermoon, in NASA's words, happens when "a full Moon coincides with the Moon's closest approach to Earth in its elliptical orbit," a point called perigee. The farthest point is called apogee.
NASA gives typical distances:
| Point in the orbit | Approximate distance from Earth |
|---|---|
| Perigee (closest) | 226,000 miles (363,300 km) |
| Apogee (farthest) | 251,000 miles (405,500 km) |
The Moon passes through both points during every orbit of about 27 days. Because the orbit wobbles and shifts with the positions of the Sun and Earth, NASA notes that the exact distances vary, so some supermoons come closer than others.
2. It is not an official term
NASA states directly that "supermoon" is not an official astronomical term. It is typically used for a full Moon that comes within at least 90 percent of perigee. That loose definition is why different sources sometimes count different numbers of supermoons in a year.
3. How much bigger and brighter?
This is where expectations and reality part ways. NASA says that at its closest, the full Moon can appear up to 14 percent bigger and 30 percent brighter than the faintest full Moon of the year, which happens when the Moon is farthest away.
NASA's comparison for the size difference: it is similar to the difference between a quarter and a nickel. Side by side, you would notice. Alone in the sky, with nothing to compare against, most people cannot tell.
NASA puts it plainly: even though 14 percent "doesn't make a big difference in detectable size," a full supermoon is a bit brighter than other moons of the year.
4. How often they happen
NASA says supermoons happen only three to four times a year, and they always come one after another, in consecutive months. For most of the year, perigee and the full Moon do not line up.
5. The next supermoons
NASA's supermoon page lists these upcoming dates:
| Date (UTC) | Time (UTC) | Eastern Time in the US |
|---|---|---|
| November 24, 2026 | 14:54 | 9:54 a.m. EST, November 24 |
| December 24, 2026 | 01:28 | 8:28 p.m. EST, December 23 |
The listed times are the moment of the full Moon, given in Coordinated Universal Time (UTC). The Eastern Time column subtracts 5 hours for Eastern Standard Time. Notice that the December supermoon falls on the evening of December 23 in the eastern United States, a day earlier than the UTC date suggests. Check your own time zone the same way.
6. Supermoon versus blue moon
The two terms often appear together, but they mean different things. NASA's explainer on super blue moons separates them:
- Supermoon: about distance. A full Moon near perigee.
- Monthly blue moon: about the calendar. The second full Moon in a single month. NASA says the Moon's cycle is 29.5 days, a bit shorter than most months, so this happens every two to three years.
- Seasonal blue moon: the third full Moon in a season that has four instead of the usual three.
A blue moon is not blue. NASA notes that on rare occasions smoke or dust in the air can scatter red light and make the Moon look bluish, but that has nothing to do with the name.
7. A small real effect: tides
A supermoon is subtle to the eye, but NASA says it does have one measurable effect on Earth: because the Moon is at its closest approach, it can cause higher tides than usual.
8. How to enjoy one
- Look for it low in the sky. A Moon near the horizon, next to trees or buildings, gives your eye something to compare it against.
- Compare it with memory, not expectation. NASA's quarter-and-nickel comparison is a fair guide to how subtle the difference is.
- Try a photo with a foreground. A distant landmark with the Moon beside it makes the size easier to appreciate.
- Mark the next pair. Since supermoons arrive in consecutive months, missing November's still leaves December's.
9. Key takeaways
- A supermoon is a full Moon near perigee, the closest point of the Moon's orbit, about 226,000 miles away.
- NASA says it is not an official term; it usually means a full Moon within 90 percent of perigee.
- At its closest, a full Moon can look up to 14 percent bigger and 30 percent brighter than the year's faintest full Moon.
- Supermoons come three to four times a year, in a row; NASA lists November 24 and December 24, 2026 (UTC).
- A blue moon is about the calendar, not distance, and it is not actually blue.