Stars are SO far away that no rocket has ever flown to one. We can't scoop up a piece of a star to test it. So here is the big puzzle:
The amazing answer: a star sends us a secret message inside its light. In this lesson you'll learn to read that message — just like a real space scientist! 🚀
Tap Next to begin.
White light from a star looks plain. But when light passes through a special glass shape called a prism, it spreads out into a rainbow of colours.
Here's the magic part. When you look very closely at a star's rainbow, some thin dark lines are missing, like gaps in a comb.
Each kind of stuff — like hydrogen or helium gas — soaks up its OWN special colours. So it leaves its OWN pattern of dark lines. It's like a barcode or a fingerprint for that material!
Those black stripes tell us which gases are in the star.
Let's explore! Tap each gas below to light up its very own barcode. Notice how every pattern is different.
A telescope caught this star's barcode (the bright lines below). Which gas's fingerprint does it match?
Compare it with each gas's fingerprint and pick the match.
Light tells us more than what a star is made of. Its colour tells us how hot it is. Blue-white stars are the hottest; red stars are the coolest.
Tap each star to check your guess: is it hot or cool?
You learned how we know what stars are made of — without ever touching one:
🌈 1. A prism splits a star's light into a rainbow.
📊 2. Dark lines in the rainbow make a barcode.
🔬 3. Every gas has its own barcode fingerprint.
🕵️ 4. Match the star's barcode to find its gases.
🔥 5. The star's colour tells us how hot it is.
This real science is called spectroscopy. Next time you see a star, remember — its light is whispering its secrets, and now you know how to listen. 💫
Tap Start again to explore once more!