Instructed to work out the brightness of particular stars captured by NASA’s TESS (Transiting Exoplanet Survey Satellite), Wolf Cukier, NASA’s intern, by mere chance, discovered a new planet seven times the size of Earth.

A 17-year-old intern was searching in a database “for everything the volunteers had flagged as an eclipsing binary, a system where two stars circle each other, and from our view eclipse each other every orbit.” A stellar eclipse at first thought, by examining transits (small dips in starlight), it later turned out to be TOI 1338 b—the first planet discovered by TESS, situated some 13,000 light-years away from Earth, in the constellation known as Pictor. Being a circumbinary planet, it revolves around two stars, and its size is approximately seven times bigger than the size of ours, or almost the size of Saturn.

See the explanation video by NASA below to learn how the planet was found.