'We are stardust' is more than a lyric in a hit 1970s song. It’s actually true. Our solar system began as flecks of star-created gas and dust, that drew together to form our sun, the planets ... and us. And there was plenty of dust left over. So, as NASA's New Horizons spacecraft prepares for the world’s first-ever fly by of Pluto (July 14), dust is one of the data points. From Boulder, Colorado, Shelley Schlender reports about the Student Dust Counter.