williams high school in, alexandr virginia, anna humphrey. >> reporter: it's the biggest ience competition in the country, and alexandria, virginia, native, anna humphrey has won it. >> being a part of the science talent search has been a dream of mine sin the sixth grade. >> reporter: the science talent search comes with more than jusg brag rights. as the first place winner, anna takes home $250,000. >> it's goi to take a while for this all to sink in, for sure. >> reporter: this is anna and her father in the hls of tc williams high school, where she is a senior, and he happens to be a teacher. >> not only proud of all she's done, but also reallyf proud how the schools here, and the teachers she's had really supported her over the years. >> my goal was to figure out how massive e planet could be. >> reporter: how did shelaim is national honor? 's her work all of this research on exoplanets,lanets that orbit stars beyond our solar system. >> if you have a larger planet, the possible places it could fit get smaller. i'm a space nerd, as simple as that. >> reporter: and her school couldn't b