Phases of the Moon

Why does the Moon look different every night? It's not actually changing — we're just seeing different parts of its sunlit half. This 90-second narrated lesson teaches kids about the eight phases of the Moon. Includes a quiz.

Class 6 ScienceClass 6 / Grade 6Ages 8–11
Lesson
🌗 Phases of the Moon
The Moon keeps changing shape!Why? The Moon doesn't actually change.

Look up at the night sky for a few weeks in a row. The Moon keeps changing shape. Sometimes it's a thin sliver, sometimes a half-circle, sometimes a perfectly round ball. But here's the secret — the Moon itself never actually changes.

The Moon orbits Earth

The Moon is a rocky ball about a quarter the size of Earth. It travels around our planet in a roughly circular path called an orbit. One complete orbit takes about 28 days. That's why the cycle of moon phases also takes about a month.

The Moon doesn't make its own light

Here's the secret to phases — the Moon doesn't shine. The bright white of a full moon is just sunlight bouncing off its surface. At any moment, only one half of the Moon is lit. The other half is in darkness. This never changes — what changes is how much of the lit half WE can see from Earth.

The eight phases

  1. New Moon — lit side faces away from us; we see nothing
  2. Waxing crescent — a thin sliver on the right grows
  3. First quarter — half the Moon is bright
  4. Waxing gibbous — most of the Moon is lit
  5. Full Moon — entire face is bright
  6. Waning gibbous — slowly shrinking from the right
  7. Last quarter — other half is bright
  8. Waning crescent — sliver on the left, getting thinner

Waxing vs waning

Waxing means growing. Waning means shrinking. From new Moon to full Moon, the lit part grows every night — that's the waxing half. From full Moon back to new Moon, the lit part shrinks — the waning half.

Indian festivals follow the moon

Many Indian festivals are based on the Moon's cycle. Diwali falls on the new Moon. Karva Chauth is celebrated when the Moon appears as a thin crescent. Sharad Purnima is on the autumn full Moon. The lunar calendar is one of the oldest ways humans kept time.

Frequently asked questions

Why does the Moon look different shapes on different nights?

Because we see different amounts of the Moon's sunlit half as it orbits Earth. The Moon itself isn't changing — only our viewing angle is.

What is a 'full moon'?

A full moon happens when the entire face of the Moon facing Earth is lit by the Sun. That's only possible when the Moon is on the opposite side of Earth from the Sun.

Why can we sometimes see the Moon during the day?

The Moon is up in the sky for about half the time, day or night. When the daytime Moon is bright enough (especially near full or waxing/waning), it can be seen even with the Sun out.

Why is one side of the Moon always facing away from us?

The Moon is 'tidally locked' to Earth — it spins on its axis at the same rate it orbits Earth, so the same side always faces us. The 'far side' was first photographed by a Soviet spacecraft in 1959.

What's the difference between waxing and waning?

Waxing = growing (new Moon → full Moon). Waning = shrinking (full Moon → new Moon). A waxing crescent appears on the right; a waning crescent appears on the left.

How does the lunar calendar work?

Many calendars (Hindu, Islamic, Chinese) follow the Moon's cycle. A 'lunar month' lasts about 29.5 days — from one new moon to the next. Many Indian festivals are timed by this calendar.

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