Mary Masterman, 17, has loved science since she was little. "I can't remember ever not being interested," she says. On March 13, Mary earned first prize--a $100,000 college scholarship--in the Intel Science Talent Search. Mary invented an affordable spectrograph, a tool used in astronomy and medicine that measures wavelengths. It can also be used to look for hidden explosives. Spectrographs can cost up to $100,000, but Mary made hers for less than $1,000.