How do scientists find planets around other stars?

Scientists usually find faraway planets by noticing what they do to their stars. A planet can make starlight dim when it passes across our view, or make the star sway because of gravity's pull. Those patterns let astronomers measure planets they cannot see directly.

One lovely detail is how patient the work can be. Kepler watched huge crowds of stars, waiting for regular blinks that repeated like a clock. From those blinks, scientists can estimate a planet's size, year length, and sometimes whether it might have air.