How do scientists detect exoplanets orbiting distant stars?

Scientists use clever tricks to find planets that are far away and too small to see.

Imagine you're on a playground swing, and your friend is pushing you. You can feel the push, it makes you go higher. Scientists watch stars in the same way. When a planet orbits its star, it gently pulls the star back and forth, like a tiny tug-of-war. This change is so small that scientists need special tools to see it.

If you're on a swing and your friend pushes you, the swing moves, you can see it. Scientists use telescopes to watch stars, and when they notice a star getting slightly dimmer and brighter again, like a flickering light, that means a planet is passing in front of it.

Sometimes, scientists see a shadow pass over a star. It’s like holding up your hand between you and a lamp, the lamp gets a little darker. When the planet moves behind its star, scientists see this tiny shadow, and they know there's a planet hiding in space!