Directional Aspects of Vegetation Linear and Circular Polarization Biosignatures
| Autor: | C.H. Lucas Patty, Antoine Pommerol, Jonas G. Kühn, Brice-Olivier Demory, Nicolas Thomas |
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| Rok vydání: | 2023 |
| Předmět: |
Earth and Planetary Astrophysics (astro-ph.EP)
Extraterrestrial Environment 530 Physics 520 Astronomy FOS: Physical sciences Biomolecules (q-bio.BM) 500 Science 620 Engineering Agricultural and Biological Sciences (miscellaneous) Quantitative Biology - Biomolecules Biological Physics (physics.bio-ph) Space and Planetary Science FOS: Biological sciences Physics - Biological Physics Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | Astrobiology. 22(9) |
| ISSN: | 1557-8070 |
| Popis: | Homochirality is a generic and unique property of all biochemical life and is considered a universal and agnostic biosignature. Upon interaction with unpolarized light, homochirality induces fractional circular polarization in the light that is scattered from it, which can be sensed remotely. As such, it can be a prime candidate biosignature in the context of future life-detection missions and observatories. The linear polarizance of vegetation is also sometimes envisaged as a biosignature, although it does not share the molecular origin as circular polarization. It is known that the linear polarization of surfaces is strongly dependent on the phase angle. The relation between the phase angle and circular polarization stemming from macromolecular assemblies, such as in vegetation, however, remained unclear. We demonstrate in this study using the average of 27 different species that the circular polarization phase angle dependency of vegetation induces relatively small changes in spectral shape and mostly affects the signal magnitude. With these results we underline the use of circular spectropolarimetry as a promising agnostic biosignature complementary to the use of linear spectropolarimetry and scalar reflectance. Comment: 37 pages, 12 figures |
| Databáze: | OpenAIRE |
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