Tonight’s Blue Moon: How to Spot the Second Full Moon of May

If you’ve ever heard the phrase “once in a blue moon,” you’re about to see why it’s more than just a saying. This Saturday night, May 31, 2024, the sky will host a second full moon in the same calendar month, a phenomenon astronomers officially call a Blue Moon. It’s not actually blue in colour, but the rarity feels just as striking.

When you step outside after sunset, you’ll notice the Moon rising high in the east just as the twilight fades. For most observers in the Northern Hemisphere, the full Moon will be at its brightest around 2:27 a.m. local time, give or take a few minutes depending on your longitude. In the Southern Hemisphere, the timing is the same, but the Moon will appear a bit lower in the sky for those further south.

Now, you might be wondering: why do we call it a “Blue” Moon at all? The name dates back to an old calendar quirk. In a typical year there are twelve full moons, one per month. Occasionally, a month squeezes in a second full Moon, and the extra one gets the nickname “Blue.” The last time this happened in May was 2007, and before that in 1999. So, while the Moon won’t actually turn sapphire‑hued, it’s still a neat reminder of how our calendars and lunar cycles sometimes clash.

Visibility is pretty generous this time around. The Moon will be high enough for anyone with a clear sky—whether you’re in New York, London, Sydney, or Johannesburg—to catch a good look. The best viewing window starts roughly an hour after sunset, when the sky is dark enough for the Moon’s silvery glow to stand out against the lingering pink hues of twilight. If you’re in a city with lots of light pollution, try finding a park or an open field away from streetlights; even a modest amount of darkness can make the Moon look more impressive.

For those who love a bit of extra detail, this Blue Moon will be a “full supermoon.” Because the Moon is near its closest approach to Earth (perigee) at the same time it’s full, it will appear about 14% larger and 30% brighter than an average full Moon. It’s a subtle difference to the naked eye, but when you compare photos taken during a regular full Moon, the size jump is noticeable.

Photography enthusiasts, take note: a tripod and a simple telephoto lens (around 200‑300 mm) will let you capture the Moon’s craters with crisp clarity. If you’re using a smartphone, try a small clip‑on telescope attachment or a steady hand and a timer to avoid shaking.

And here’s a little fun fact for the romantics: many cultures associate a Blue Moon with good luck, new beginnings, or even magical wishes. While there’s no scientific backing, it’s a charming excuse to make a wish as you watch the lunar disc climb higher.

In short, if you can find a spot with a clear view of the eastern horizon, step outside after dusk, and give the night a minute, you’ll be witnessing a once‑in‑a‑while event. Grab a blanket, maybe a warm drink, and let the Moon do its quiet, timeless thing. It’s a simple pleasure, but one that reminds us how connected we are to the rhythms of the cosmos.

So, set a reminder, tell a friend, and keep an eye on the sky this Saturday. The Blue Moon will be there, waiting—just as reliable as the tides, but a lot more spectacular.