See the impact of the giant Three Gorges dam on the Yellow River. thumbnail: http://svs.gsfc.nasa.gov/vis/a000000/a003400/a003433/damHD_v3.1309_gal.png

STELLA: A DIY Handheld Scientific Instrument
If you are looking for a do-it-yourself (DIY) handheld spectrometer, you need to meet STELLA. STELLA (Science and Technology Education for Land/Life Assessment) is a portable scientific instrument developed by