DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works
Abstract The detection of exolife is one of the goals of very ambitious future space missions that aim to take direct images of Earth-like planets. While associations of simple molecules present in the planet’s atmosphere (O2,O3,CO2, etc.) have been identified as possible global biomarkers, this pap...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.397.6312 2023-05-15T18:40:34+02:00 DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works Space Sci Rev Luc Arnold The Pennsylvania State University CiteSeerX Archives 2007 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.397.6312 http://www.obs-hp.fr/~larnold/publi_to_download/Arnold_2008_SpaceScieRev.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.397.6312 http://www.obs-hp.fr/~larnold/publi_to_download/Arnold_2008_SpaceScieRev.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.obs-hp.fr/~larnold/publi_to_download/Arnold_2008_SpaceScieRev.pdf text 2007 ftciteseerx 2016-09-25T00:08:01Z Abstract The detection of exolife is one of the goals of very ambitious future space missions that aim to take direct images of Earth-like planets. While associations of simple molecules present in the planet’s atmosphere (O2,O3,CO2, etc.) have been identified as possible global biomarkers, this paper reviews the detectability of a signature of life from the planet’s surface, i.e. the green vegetation. The vegetation reflectance has indeed a specific spectrum, with a sharp edge around 700 nm, known as the “Vegetation Red Edge ” (VRE). Moreover, vegetation covers a large surface of emerged lands, from tropical evergreen forest to shrub tundra. Thus, considering vegetation as a potential global biomarker is relevant. Earthshine allows us to observe the Earth as a distant planet, i.e. without spatial resolution. Since 2001, Earthshine observations have been used by several authors to test and quantify the detectability of the VRE in the Earth spectrum. The vegetation spectral signature is detected as a small “positive shift ” of a few percentage points above the continuum, starting at 700 nm. This signature appears in most spectra, and its strength is correlated with the Earth’s phase (visible land versus visible ocean). The observations show that detecting the VRE on Earth requires a photometric relative accuracy of 1 % or better. Detecting something equivalent on an Earth-like planet will therefore remain challenging, especially considering the possibility of mineral artifacts and the question of “red edge ” universality in the Universe. Text Tundra Unknown |
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Abstract The detection of exolife is one of the goals of very ambitious future space missions that aim to take direct images of Earth-like planets. While associations of simple molecules present in the planet’s atmosphere (O2,O3,CO2, etc.) have been identified as possible global biomarkers, this paper reviews the detectability of a signature of life from the planet’s surface, i.e. the green vegetation. The vegetation reflectance has indeed a specific spectrum, with a sharp edge around 700 nm, known as the “Vegetation Red Edge ” (VRE). Moreover, vegetation covers a large surface of emerged lands, from tropical evergreen forest to shrub tundra. Thus, considering vegetation as a potential global biomarker is relevant. Earthshine allows us to observe the Earth as a distant planet, i.e. without spatial resolution. Since 2001, Earthshine observations have been used by several authors to test and quantify the detectability of the VRE in the Earth spectrum. The vegetation spectral signature is detected as a small “positive shift ” of a few percentage points above the continuum, starting at 700 nm. This signature appears in most spectra, and its strength is correlated with the Earth’s phase (visible land versus visible ocean). The observations show that detecting the VRE on Earth requires a photometric relative accuracy of 1 % or better. Detecting something equivalent on an Earth-like planet will therefore remain challenging, especially considering the possibility of mineral artifacts and the question of “red edge ” universality in the Universe. |
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The Pennsylvania State University CiteSeerX Archives |
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Space Sci Rev Luc Arnold |
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Space Sci Rev Luc Arnold DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works |
author_facet |
Space Sci Rev Luc Arnold |
author_sort |
Space Sci Rev |
title |
DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works |
title_short |
DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works |
title_full |
DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works |
title_fullStr |
DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works |
title_full_unstemmed |
DOI 10.1007/s11214-007-9281-4 Earthshine Observation of Vegetation and Implication for Life Detection on Other Planets A Review of 2001–2006 Works |
title_sort |
doi 10.1007/s11214-007-9281-4 earthshine observation of vegetation and implication for life detection on other planets a review of 2001–2006 works |
publishDate |
2007 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.397.6312 http://www.obs-hp.fr/~larnold/publi_to_download/Arnold_2008_SpaceScieRev.pdf |
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Tundra |
op_source |
http://www.obs-hp.fr/~larnold/publi_to_download/Arnold_2008_SpaceScieRev.pdf |
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http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.397.6312 http://www.obs-hp.fr/~larnold/publi_to_download/Arnold_2008_SpaceScieRev.pdf |
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