The Moon is halfway through its monthly dance tonight, and you can see the proof with your own eyes. On September 18, 2026, the Moon enters its First Quarter phase, which means roughly half of its surface glows toward Earth.
NASA’s Daily Moon Guide tracker confirms the Moon is in the First Quarter phase as of Friday, Sept. 18. About 45% of its surface is visible from our planet, and that split is easy to spot once you know what to look for.
The Split That Shows Tonight
The First Quarter Moon is the phase where the Moon looks like a half-dollar coin hanging in the sky. The bright side catches the Sun’s light head-on, while the dark side faces away. You can see this clearly without any equipment at all.
Three large dark patches stand out even to the naked eye:
- Mare Crisium
- Mare Serenitatis
- Mare Fecunditatis
Those three features are visible without binoculars. They mark the face of the Moon as it moves through its monthly cycle.
If you have binoculars handy, you can add three more craters to your list:
- Endymion Crater
- Posidonius Crater
- Mare Nectaris
These are smaller and harder to pick out, but a pair of binocs makes the difference. Each one shows up as a distinct feature within the larger landscape.
For those with a telescope, the view gets even better. The Apollo 11 and 17 landing spots are both visible in the right gear. So is the Rupes Altai.
The phase we see is determined by the Moon’s position relative to both Earth and the Sun.
That line comes from NASA itself, explaining how the Moon changes shape from night to night. The Moon takes about 29.5 days to travel around Earth, and during that journey it passes through eight distinct phases.
From New Moon to Full Moon
The eight phases of the Moon follow a familiar pattern. Start at New Moon, when the Moon is between Earth and the Sun, and its face is dark. Then move through the Waxing Crescent, when a thin sliver of light appears on the right side.
The First Quarter comes next, with half of the Moon lit on the right side. After that, the Waxing Gibbous brings more than half of the Moon glowing, though it still falls short of full.
Then comes the Full Moon, when the whole face of the Moon is illuminated and fully visible. From there, the cycle reverses. The Waning Gibbous loses light on the right side, and the Third Quarter (or Last Quarter) shows another half-Moon, but now the left side is lit.
Finally, the Waning Crescent brings a thin sliver of light back on the left side before the Moon goes dark again and the cycle begins over.
What Happens Next
The Moon will continue to get more illuminated each night until we reach the Full Moon. The next Full Moon will take place on September 26.
For anyone who wants to keep tracking the Moon’s progress, NASA’s Daily Moon Guide tracker is the place to go. It updates regularly with the current phase, the percentage of the Moon’s surface that is visible, and what features to look for in the sky.
The Tracker And Its Author
The tracker is produced by Mashable, and its reports cover the Moon’s daily position, the percentage of its surface visible, and what features amateur observers can spot.
Lois Mackenzie is a freelance reporter at Mashable. She has written for many publications over the years, covering everything from local news to the best pair of running shoes.
Her byline also appears in Fit&Well, Metro, and Coach magazine, where she usually writes about deals on electronics and home goods, or offers guides on improving your athletic performance.
Lois also holds a Master’s degree in Digital Journalism from Strathclyde University and obtained a Master of Arts in English Literature at the University of Aberdeen.
What To Look For Tonight
If you want to see the First Quarter Moon for yourself, the best advice is simple: look up. The dark patches are the easiest to spot. Mare Crisium, Mare Serenitatis, and Mare Fecunditatis are visible without any equipment.
Once you have them locked in, the smaller craters become easier to find. Binoculars will show you Endymion, Posidonius, and Mare Nectaris. A telescope will reveal the Apollo landing sites and the Rupes Altai.
But the core of the experience is free: step outside, look up, and watch the Moon change shape.
The Moon’s phases are a weekly reminder that the sky is not fixed. It moves, it changes, and it rewards anyone who takes a moment to look. Tonight is the First Quarter, and the Full Moon arrives on September 26.
Source material: “Moon phase today: What the Moon will look like on September 18, 2026,” Mashable.
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