Did you know that photosynthesising plants behave a bit like glow in the dark toys? Neither did I.
After the chlorophyll in a plant has absorbed sunlight, the core of the photosynthetic machinery gives off a red glow – fluorescence. This reflects how efficiently the plant is photosynthesising, or how well it is ‘breathing’ and, therefore, how healthy it is.
And the European Space Agency is currently developing a satellite that can detect this glow. The purpose is to detect where and which vegetation is currently producing the most oxygen. So far the project has been limited to testing on airplanes. This glow is quite hard to detect, and has until recently been almost impossible to measure outside a laboratory. But so far tests have been very successful, you can see an image they have taken of this glow below.
The image shows fluorescence from different types of vegetation. It was captured by a novel airborne sensor called Hyplant to support the development of ESA’s candidate Earth Explorer FLEX mission. The highest fluorescence values (bright yellow–green) were found in sugar beet. These results show how the FLEX satellite mission could provide global maps of vegetation fluorescence, which can be used to retrieve the actual photosynthetic activity. In turn, this would not only improve our understanding of the amount of carbon stored in plants and their role in the carbon and water cycles, but could potentially also be important for helping to optimise agricultural productivity.