Biosignatures of the Earth : I. Airborne spectropolarimetric detection of photosynthetic life
(2021) In Astronomy and Astrophysics 651.- Abstract
Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this circularly polarized light can be sensed remotely, it can be one of the most compelling candidate biosignatures in life detection missions. While there are also other sources of circular polarization, these result in spectrally flat signals with lower magnitude. Additionally, circular polarization can be a valuable tool in Earth remote sensing because the circular polarization signal directly relates to vegetation physiology. Aims. While high-quality circular polarization measurements can be obtained in... (More)
Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this circularly polarized light can be sensed remotely, it can be one of the most compelling candidate biosignatures in life detection missions. While there are also other sources of circular polarization, these result in spectrally flat signals with lower magnitude. Additionally, circular polarization can be a valuable tool in Earth remote sensing because the circular polarization signal directly relates to vegetation physiology. Aims. While high-quality circular polarization measurements can be obtained in the laboratory and under semi-static conditions in the field, there has been a significant gap to more realistic remote sensing conditions. Methods. In this study, we present sensitive circular spectropolarimetric measurements of various landscape elements taken from a fast-moving helicopter. Results. We demonstrate that during flight, within mere seconds of measurements, we can differentiate (S∕ N > 5) between grass fields, forests, and abiotic urban areas. Importantly, we show that with only nonzero circular polarization as a discriminant, photosynthetic organisms can even be measured in lakes. Conclusions. Circular spectropolarimetry can be a powerful technique to detect life beyond Earth, and we emphasize the potential of utilizing circular spectropolarimetry as a remote sensing tool to characterize and monitor in detail the vegetation physiology and terrain features of Earth itself.
(Less)
- author
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Astrobiology, Earth, Planets and satellites: surfaces, Planets and satellites: terrestrial planets, Polarization, Techniques: polarimetric
- in
- Astronomy and Astrophysics
- volume
- 651
- article number
- A68
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85110468540
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/202140845
- language
- English
- LU publication?
- yes
- id
- 35102c77-e4b6-4cc9-846b-1b610457b554
- date added to LUP
- 2021-09-08 16:44:37
- date last changed
- 2024-04-20 10:57:16
@article{35102c77-e4b6-4cc9-846b-1b610457b554,
abstract = {{<p>Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this circularly polarized light can be sensed remotely, it can be one of the most compelling candidate biosignatures in life detection missions. While there are also other sources of circular polarization, these result in spectrally flat signals with lower magnitude. Additionally, circular polarization can be a valuable tool in Earth remote sensing because the circular polarization signal directly relates to vegetation physiology. Aims. While high-quality circular polarization measurements can be obtained in the laboratory and under semi-static conditions in the field, there has been a significant gap to more realistic remote sensing conditions. Methods. In this study, we present sensitive circular spectropolarimetric measurements of various landscape elements taken from a fast-moving helicopter. Results. We demonstrate that during flight, within mere seconds of measurements, we can differentiate (S∕ N > 5) between grass fields, forests, and abiotic urban areas. Importantly, we show that with only nonzero circular polarization as a discriminant, photosynthetic organisms can even be measured in lakes. Conclusions. Circular spectropolarimetry can be a powerful technique to detect life beyond Earth, and we emphasize the potential of utilizing circular spectropolarimetry as a remote sensing tool to characterize and monitor in detail the vegetation physiology and terrain features of Earth itself. </p>}},
author = {{Patty, C. H.Lucas and Kühn, Jonas G. and Lambrev, Petar H. and Spadaccia, Stefano and Jens Hoeijmakers, H. and Keller, Christoph and Mulder, Willeke and Pallichadath, Vidhya and Poch, Olivier and Snik, Frans and Stam, Daphne M. and Pommerol, Antoine and Demory, Brice Olivier}},
issn = {{0004-6361}},
keywords = {{Astrobiology; Earth; Planets and satellites: surfaces; Planets and satellites: terrestrial planets; Polarization; Techniques: polarimetric}},
language = {{eng}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{Biosignatures of the Earth : I. Airborne spectropolarimetric detection of photosynthetic life}},
url = {{http://dx.doi.org/10.1051/0004-6361/202140845}},
doi = {{10.1051/0004-6361/202140845}},
volume = {{651}},
year = {{2021}},
}