In previous Franklin Facts, I've shown how satellites can measure properties of water bodies such as water temperature and wave height. Now, add water quality to that list, a breakthrough that may allow us to use space-borne instruments to answer questions such as "Are the fish in that lake safe to eat?"

The key to this new monitoring capability is measuring how much radiation the water reflects, which is linked to how turbid, or cloudy the water is. This in turn, can be used to infer information about water quality, data that, to this point, is gathered by hand at relatively few monitoring sites.

Satellites can provide the wide coverage needed for large bodies of water that cover hundreds or even thousands of acres. But right now, the satellite can only resolve areas about a half-mile on a side, not fine enough to give small-scale detail to the water quality information. The next generation of sensors will provide perhaps 20 times higher resolution, which may allow satellites to have input in deciding whether the legendary bass from a local lake are fit for the dining room table.