Lit and unlit halves

The idea

The Moon emits no light of its own and shines by reflecting sunlight, so the half facing the Sun is illuminated and the half facing away is not; the Moon's actual shape never changes.

Is the Moon a lamp?

The Moon shines in the night sky.

Does the Moon make its own light?

• No, it reflects sunlight
• Yes, like the Sun
• Yes, but weakly

Sunlight on the Moon

Press Next step.

Reflected light

The Moon does not emit light of its own. It shines because it reflects the sunlight that falls on it. The half facing the Sun is lit. The other half is dark. The Moon's actual shape never changes.

The Moon emits no light of its own; it reflects sunlight. The half facing the Sun is lit, the other half is not. The Moon's actual shape never changes.

Notes

The Moon reflects sunlight; the half facing the Sun is lit. Its real shape never changes.

Check yourself

The Moon shines because it …

Which half of the Moon is illuminated?

Does the actual shape of the Moon change?

The half of the Moon facing away from the Sun is …

• makes its own light. The Moon emits no light of its own.
• burns like the Sun. The Moon reflects sunlight.
• reflects sunlight — correct. Yes!
• The half facing the Sun — correct. Yes!
• The half facing away from the Sun. That half does not get sunlight.
• Always the half facing Earth. The lit half is the one facing the Sun.
• Yes, it shrinks and grows. The Moon's shape never changes.
• No, only what we see changes — correct. Yes!
• Yes, it becomes flat. The Moon's actual shape never changes.
• illuminated. It receives no sunlight.
• hot and bright. It receives no sunlight.
• not illuminated — correct. Yes!