1 item with the tag “photosynthesis

  • The Long Wavelength Limit of Oxygenic Photosynthesis
    NAI 2013 VPL at University of Washington Annual Report

    Oxygenic photosynthesis (OP) produces the strongest biosignatures at the planetary scale on Earth: atmospheric oxygen and the spectral reflectance of vegetation. Both are controlled by the properties of Chlorophyll a, its ability to perform the water-splitting to produce oxygen, and its spectral absorbance that is limited to red and shorter wavelength photons. We seek to answer what is the long wavelength limit at which OP might remain viable, and how. This would clarify whether and how to look for OP adapted to the light from red dwarfs or M stars, which emit little visible light but abundant far-red and near-infrared. Very recently discovered cyanobacteria have been found to harbor alternative chlorophylls adapted to spectral light environments very much like that of M stars. This projects uses field, lab, and modeling studies to study these far-red adapted cyanobacteria as analogues for extrasolar oxygenic photosynthesis pushing the long wavelength limit.

    ROADMAP OBJECTIVES: 3.2 4.2 5.1 5.3 6.2 7.2