The next full Moon will occur on Thursday, May 23. That evening, the Moon will rise at 9:15 p.m. EDT.
How to See the Next Full Moon
The full Moon technically peaks in the middle of the morning on May 23, while the Moon is below the horizon, but you don't have to be watching at the very moment of its peak to see the Moon completely full. Between lunar libration and the fact that the Moon appears full for a day or so before and after its peak, stargazers need not stay awake into the wee hours just to catch a glimpse. Moonrise comes at about 9:15 p.m. EDT on May 22-24, so you'll be able to see the full Moon sailing across the sky from anywhere with clear weather.
To get the best view of May's full Moon, look to the southeast after sundown, toward the end of evening twilight.
Moon Phases For May
Here are the phases of the Moon for this lunar cycle:
🌗 Last Quarter: May 1, 7:27 a.m. EDT (11:27 GMT)
🌑 New Moon: May 7, 11:22 p.m. EDT (03:22 GMT)
🌓 First Quarter: May 15, 7:48 a.m. EDT (11:48 GMT)
🌕 Full Moon: May 23, 9:53 a.m. EDT (13:53 GMT)
Full Moon Lore: The Flower Moon
April showers bring May flowers—but what do May flowers bring? (Other than Pilgrims and allergies?) The Flower Moon! All over the Northern Hemisphere, May's full Moon is known as the Flower Moon, in homage to the leaf and flower buds on what seems like every tree and shrub.
Other notable names for the May lunar cycle include the Planting Moon (attributed to the Dakota/Lakota), since this is the time during which the danger of frost finally passes and it becomes safe to plant the year's crops. Animals start to shed their winter coats. As night falls, the little frogs start to sing, and robins warble in the grass. Thus the May full moon also came to be called the Frog Moon or the Egg Laying Moon (attested Cree), and the Moon of the Shedding Ponies (Oglala).
Lunar Cycles
Full moons get all the attention, especially since lunar eclipses like the one this March can only happen during a full Moon. But solar eclipses, like the total solar eclipse on April 8, can only happen during the new Moon—when the Sun, Moon, and Earth line up perfectly in space, with the Moon in the middle.
Not every planet with moons even has eclipses; if our Moon was smaller or farther away, it wouldn't cover the entire face of the Sun, and we'd have only annular eclipses or transits instead. But ours lines up just right, like Goldilocks and her bowl of porridge. So why isn't there an eclipse every two weeks?
The short answer is that we don't get eclipses every lunar month because the Moon got tilted. No, literally. The Moon's orbit is tilted with respect to the Earth's, so most of the time, the Moon appears above or below the Sun.
Orbital Dynamics
Just as the Earth's orbital axis is inclined about 23 degrees with respect to the greater plane of the solar system, the axis about which the tidally locked Moon orbits the Earth is tilted—but at a different relative angle than Earth's axis. (The Moon's orbital plane is flattened back toward the ecliptic, at just a 5.1° inclination.) This means the Moon drifts north and south over the course of a lunar month, above and below its own equator. The points at which its orbit crosses the ecliptic are called nodes.
Eclipses are only possible when the Moon crosses the ecliptic. At the same time, the alignment and orientation of the Moon's orbit aren't fixed with respect to the Earth; they change over time in a process called precession. For an observer on Earth, lunar nodes appear to rotate west by about 19.4° per year. It's like a hula hoop, or a Spirograph. Changing though its alignment may be, the precession of the Moon does eventually come around in a complete cycle. The combination of these two cycles adds up to a 19-year period of 223 to 242 lunar months, depending on how you define a lunar month, called a Saros cycle (or an enneadecaeteris, from the Ancient Greek ἐννεακαιδεκαετηρίς or "nineteen").
Sacred Geometry
Celestial patterns like the Saros cycle have fascinated astronomers for thousands of years. Eclipses separated by a Saros cycle will have very similar geometry, and thus very similar paths. The Moon's dance from north to south and back again shows up in places like Stonehenge, the earliest part of which dates to about 3100 BC.
Even our calendar is based in part on lunar eclipses. Four Saros cycles put together makes one Calippic cycle: a 76-year period with a year averaging 365.25 days long, and the basis of the Julian calendar. It took another 1,600 years to refine the Julian calendar into the Gregorian calendar, a nudge that lengthened a year by less than one hour per century.
Eclipses once swayed the hand of princes, because they are both astonishing and (with some intimidating math) predictable. Saros cycles were known to the Chaldean astronomers and astrologers of Babylonia as a period when lunar eclipses seem to repeat themselves. In other contexts, such as the making of liturgical calendars among people of the Book, the period is known as the Metonic cycle. The Saros cycle also shows up as a dial on the Antikythera Mechanism: the oldest known analog computer, which is now thought to have been a tool for predicting eclipses, made in the second century BC. 🌕
