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Moon phase names

What are the moon phases called?

The eight Moon phases are new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter and waning crescent. The cycle repeats about every 29.5 days.

Try the question

What are the Moon phases called?

Move in eighths of an orbit and use the position, not just the shape, to learn each phase name.

new moonSunEarthnewwaxing crescentfirst quarterwaxing gibbousfullwaning gibbouslast quarterwaning crescent
What changed New moon: 0% of the Earth-facing disc is lit, although half of the Moon is still in sunlight.

Watch for: Quarter means a quarter of the orbit, even though the disc looks half lit.

Open this experiment in the full Moon lab

Where the Moon stands against the Sun right now. That angle is tonight’s phase — the names are just addresses along the lap.

Why “first quarter” looks like a half

At first quarter you see a half-lit disc, and the name is still right — it counts the orbit, not the light. The Moon is a quarter of the way around its lap when we see half its lit side. The names track the journey; the shapes track the lighting. Once you know that, “last quarter” stops being confusing too: three-quarters of the way around, the other half lit.

How to read tonight’s moon

Two questions identify any phase: how much is lit, and which side is lit. Less than half is a crescent, more than half is gibbous. North of the equator, a moon lit on the right is waxing — heading toward full — and lit on the left is waning; south of the equator the two swap, because you are looking at the same Moon the other way up. Your town’s moon page names tonight’s phase and the 30-day strip shows the whole run.

The same instant, the whole world over

The phase is the angle between the Sun and the Moon, so everyone on Earth sees the same phase at the same moment — there is no city where it is first quarter while another has full. What changes with where you stand is which way up the shape hangs, and when the Moon rises. That is why phase pages can be global while moonrise pages have to know your town.

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Where the turning points really are

New moon is not “no moon” — it is the Moon standing in the Sun’s direction, its lit half facing away from us, up all day and lost in the glare. Full is the opposite station, and it is the only night the Moon is up from sunset to sunrise. Scrub the simulator across a month and you can watch each name arrive as an angle, not as a picture on a calendar.

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On the hub: Moon · Sun–Earth–Moon simulator