It’s safe to assume that the average teenager has, at best, only a vague idea of what a spectrograph is, never mind how the precision instrument really works.But 17-year-old Mary Masterman, a senior at Westmoore High School in Oklahoma City, is not your average teenager. Not only does she know what the scientific device is and how it works, she also knows exactly how to build a fully functional one from scratch.Her working spectrograph so impressed judges from the Intel Science Talent Search that, in March, they named her the winner of the 66th annual competition during a reception in Washington. Masterman’s project beat out more than 1700 others submitted by students from across the US for the top prize of a $100,000 scholarship from the Intel Foundation.Masterman’s Littrow spectrograph was constructed from lenses, a laser, aluminum tubing and a camera. Her finished product cost less than $1000 (compared with commercial devices, which sell for as much as $100,000) and can accurately identify the molecular “fingerprint” of various household objects and solvents. She compared her results with published wave numbers.The most difficult part was machining the parts and then properly aligning the optics (lenses from a microscope and camera). She used an inexpensive laser as a light source, which, despite its shortcomings, still allowed for accurate wavelength measurements. Winning scientific competitions is becoming something of a habit for the teenager. Last year she won the 2005 National Young Astronomer Award for investigating the composition of stars, nebulae and galaxies.Not surprisingly, Masterman is ranked first in her high school class of 658 students. She is hoping to attend either MIT in Cambridge, Mass., or California Institute of Technology in Pasadena. She wants to become a physicist or a chemist.