Look up on different nights and the Moon looks different — sometimes a thin smile, sometimes a big round ball, sometimes hiding away.
But here is a secret: the Moon is always a round ball. It never really changes shape at all! So what is going on?
Let's become Moon detectives and solve the mystery together. Tap Next when you're ready!
The Sun is like a giant lamp. The Moon is more like a mirror — it has no light of its own, so it shines by bouncing the Sun's light back to us.
Sunlight travels across space and lights up the Moon for us.
Because sunlight comes from one side, exactly half of the Moon is always lit up — the half facing the Sun. The other half is in shadow, like night-time on the Moon.
The right half catches the sunlight. The left half stays dark.
So the Moon doesn't change shape — it just has a bright half and a dark half, always.
The Moon travels in a big circle around the Earth. As it moves, we on Earth see different amounts of its bright half — and that's the shape we notice!
Tap a Moon on its journey around Earth 👇
What you see from Earth that night:
Try every spot in the circle to see all the shapes.
The Moon takes about 29 days — roughly one month — to travel all the way around the Earth. Drag the slider to speed through a whole month and watch the shape change!
👈 New • Full 🌕 • back to New 👉
Slide slowly and watch the bright part grow, then shrink again.
Scientists have special words for the two halves of the journey:
The bright part is growing bigger each night.
The bright part is shrinking smaller each night.
Tap the right word for this Moon — it gets a little brighter every night:
You're a Moon expert now. Look at the shape and tap its name. A wrong tap is okay — you can try again!
The Moon never really changes shape. We just see different parts of its bright half as it circles the Earth.
Tonight, look up at the sky and see if you can name the Moon's shape! 🔭