How do scientists find planets around other stars?

Astronomers detect exoplanets using several techniques, with the transit method and radial velocity method being especially important. In a transit, a planet briefly blocks a small fraction of the star’s light, causing a measurable dip in brightness. In radial velocity, a planet’s gravity makes the star wobble slightly, shifting the star’s light spectrum through the Doppler effect. Missions like NASA’s Kepler and TESS have found thousands of exoplanet candidates this way. Some planets are then confirmed by combining multiple methods or using direct imaging in rare cases.