Science Common Sense

574 - How do we know about the existence of exoplanets?

There are a few ways we know about the existence of exoplanets.

1. Wobbling stars: When a planet orbits a star, it pulls on the star, making it wobble (or move back and forth). By looking at this wobble, we can figure out if a planet is there.

2. Dimmer stars: When a planet passes in front of a star, it blocks some of the star's light, making it dimmer for a short time. We can see this dimming and figure out if it's a planet.

3. Planet's heat: Some planets give off heat (or light) that we can see with special tools. This heat can tell us that a planet is there.

4. Gravitational lensing: Sometimes, the gravity of a planet can bend the light from a star, creating a "lens" effect. By looking at this effect, we can figure out if a planet is there.

By using these methods, scientists have discovered thousands of exoplanets so far, and they're still finding more.