What is the transit method in exoplanet hunting?

The transit method looks for regular decreases in starlight caused when a planet crosses the face of its star from our point of view. The amount of dimming gives scientists an estimate of the planet’s size, while the time between dips reveals its orbital period. NASA’s Kepler mission, launched in 2009, used this technique to discover thousands of exoplanet candidates. The method works best when the planet’s orbit is aligned so that transits are visible from Earth or from a spacecraft’s vantage point.