Moon Phases: Names, Order and How They Work

Every night I look at the Moon and it is different: yesterday a tiny sliver, today a bigger piece, a week from now round and bright. The Moon is not changing size. What changes is how much of its lit side we can see.

Here you get the eight moon phases in order, the reason behind them, how long the cycle lasts and a flashlight experiment to watch it all happen at home.

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Why the Moon changes shape

The Moon makes no light of its own: it reflects sunlight. Half of it is always lit. What changes through the month is how much of that lit half faces us on Earth, as the Moon travels around our planet.

The eight moon phases in order

1. New moon: the Moon sits between Earth and the Sun, and its lit side faces away. It is almost invisible.
2. Waxing crescent: a thin sliver of light appears.
3. First quarter: half the disc is lit, a week after new moon.
4. Waxing gibbous: more than half lit, nearly full.
5. Full moon: the whole disc is lit.
6. Waning gibbous: it starts losing light.
7. Last quarter: half the disc is lit again, on the opposite side.
8. Waning crescent: a thin sliver again, before the next new moon.

Waxing means the lit part is growing. Waning means it is shrinking.

How long the cycle lasts

From one new moon to the next takes about 29.5 days. That is where the idea of a "month" comes from. Each main phase (new, first quarter, full and last quarter) arrives about seven days apart.

The Northern and Southern Hemispheres see it differently

The Moon is the same for everyone, but its look changes with the hemisphere:

• In the Northern Hemisphere, a waxing moon grows from the right side.
• In the Southern Hemisphere, a waxing moon grows from the left side.

Fun facts

• The Moon always shows the same face to Earth.
• The average distance from Earth to the Moon is about 384,000 km (238,900 miles).
• The Moon pulls on the oceans and causes the tides.
• Full moon and new moon happen when Earth, Moon and Sun line up, and the tides are strongest.

Experiment: phases with a flashlight and a ball

1. In a dark room, set a lit flashlight on a table. It is the Sun.
2. Hold a ball (styrofoam or crumpled paper) in front of your face, a bit away from the flashlight. The ball is the Moon and your head is Earth.
3. Slowly turn your body so the ball goes around you.
4. Watch the lit part of the ball change: new, crescent, full, waning.

Lighting up the sky in Lumora

Lumora's motto is to light up the sky, one word at a time. Each floating island has clues and words to find, and the home screen shows the button to play the next level.

PolarzinhoLight up the sky, one word at a time. I light up one moon phase a night.

FAQ

What are the phases of the Moon?

New moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter and waning crescent.

How long is the lunar cycle?

About 29.5 days.

What does waxing mean?

The lit part of the Moon is growing.

Does Earth's shadow cause the moon phases?

No. The phases come from the angle we see the Moon's lit side from. Earth's shadow only causes lunar eclipses.

Your turn

Tonight, look at the Moon and say which phase it is. Is it waxing or waning? Which side is lit?

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