The Top 5 images from the USGS “Earth As Art” collection. thumbnail: http://svs.gsfc.nasa.gov/vis/a010000/a011000/a011052/Earth_as_Art_Top_5_youtube_hq_gal.png

Above the Earth, Below the Surface: Landsat’s Role in Monitoring Water Quality
Safeguarding freshwater resources is crucial, and while scientists use a variety of ground-based techniques to gauge water quality, the Landsat program has provided water quality data from orbit for decades.