Moon Phase Today: What to See in the Sky on September 20, 2026

Look up tonight – the Moon is already putting on a show. It’s the ninth night of the lunar cycle, which means we’re deep in the waxing‑gibbous stage and only a few days away from a full moon.

According to NASA’s Daily Moon Guide, the Moon on Sunday, September 20, 2026 is about 64 % illuminated. In plain language, more than half of the bright side is visible, but the perfect circle isn’t there yet. That extra glow makes the Moon look larger and brighter than earlier nights, and it’s a great excuse to step outside after dinner.

If you’re just using the naked eye, try to spot a few of the big, dark patches that the ancients called “seas.” You should be able to make out the Mare Vaporum (the Sea of Vapors) and the Mare Serenitatis (Sea of Serenity) low on the eastern horizon. A quick glance to the south‑west will reveal the striking Tycho crater, its bright rays fanning out like spokes on a wheel.

Got a pair of binoculars? They’ll pull out a few more details: the shallow Alphonsus crater, the rugged Posidonius crater, and the jagged outline of the Apennine Mountains become clearer. And if you happen to have a telescope, you can even spot the historic Apollo landing sites – Apollo 11, 16, and 17 – tucked away in the lunar highlands.

Wondering when the full moon arrives? Mark your calendar for September 26, when the Moon will finally be fully illuminated, offering the classic round disk that photographers love.

Why does the Moon change shape at all? As it orbits Earth – a journey that takes about 29.5 days – we see different slices of its sun‑lit side. The geometry between the Sun, Earth, and Moon determines how much of that bright side is visible from our perspective. The eight classic phases are:

• New Moon – the Moon sits between Earth and the Sun, leaving the side we face in darkness.
• Waxing Crescent – a thin sliver of light appears on the right side (for observers in the Northern Hemisphere).
• First Quarter – half the Moon is lit on the right, looking like a perfect half‑circle.
• Waxing Gibbous – more than half is illuminated, but not yet full.
• Full Moon – the entire face glows.
• Waning Gibbous – the light starts receding on the right side.
• Third (Last) Quarter – the opposite half is lit.
• Waning Crescent – a thin sliver remains on the left before the cycle restarts.

All of these phases repeat month after month, giving sky‑watchers a reliable rhythm to follow. So tonight, take a moment to enjoy the waxing‑gibbous Moon, perhaps snap a photo, or simply let its silvery light spark a bit of wonder.