NASA scientists have established a new way to use satellites to measure what's occurring inside plants at a cellular level. Plants grow and thrive through photosynthesis, a process that converts sunlight into energy. During photosynthesis, plants emit what is called fluorescence -- light invisible to the naked eye but detectable by satellites orbiting hundreds of miles above Earth. NASA scientists have now established a method to turn this satellite data into global maps of the subtle phenomenon in more detail than ever before.

Source: Seeing photosynthesis from space: NASA scientists use satellites to measure plant health