How do we spot something as tiny and faint as a planet trillions of miles away? The trick is to look at the star! So far, most of the exoplanets – worlds beyond our solar system – we’ve found were detected by looking for tiny dips in the brightness of their host stars! These dips are caused by the planet passing between us and its star – an event called a “transit.”
NASA’s newest planet hunter, the Transiting Exoplanet Survey Satellite (TESS), will seek out transits around 200,000 of the nearest and brightest stars in the sky.