Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets

Fuente: arXiv
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Auteurs principaux: Borges, Schuyler R., Jones, Gabrielle G., Robinson, Tyler D.
Format: Preprint
Publié: 2024
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author Borges, Schuyler R.
Jones, Gabrielle G.
Robinson, Tyler D.
author_facet Borges, Schuyler R.
Jones, Gabrielle G.
Robinson, Tyler D.
contents Modeling the detection of life has never been more opportune. With next generation space telescopes, like the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially similar to Earth. However, currently, few realistic planetary spectra containing surface biosignatures have been paired with direct imaging telescope instrument models. Therefore, we use a HWO instrument noise model to assess the detection of surface biosignatures affiliated with oxygenic, anoxygenic, and nonphotosynthetic extremophiles. We pair the HWO telescope model to a 1-D radiative transfer model to estimate the required exposure times necessary for detecting each biosignature on planets with global microbial coverage and varying atmospheric water vapor concentrations. For modeled planets with 0% - 50% cloud coverage, we determine pigments and the red edge could be detected within 1,000 hours (100 hours) at distances within 15 pc (11 pc). However, tighter telescope inner working angles (2.5 lambda/D) would allow surface biosignature detection at further distances. Anoxygenic photosynthetic biosignatures could also be more easily detectable than nonphotosynthetic pigments and the photosynthetic red edge when compared against a false positive iron oxide slope. Future life detection missions should evaluate the influence of false positives on the detection of multiple surface biosignatures.
format Preprint
id arxiv_https___arxiv_org_abs_2404_16126
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets
Borges, Schuyler R.
Jones, Gabrielle G.
Robinson, Tyler D.
Earth and Planetary Astrophysics
Modeling the detection of life has never been more opportune. With next generation space telescopes, like the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky exoplanets potentially similar to Earth. However, currently, few realistic planetary spectra containing surface biosignatures have been paired with direct imaging telescope instrument models. Therefore, we use a HWO instrument noise model to assess the detection of surface biosignatures affiliated with oxygenic, anoxygenic, and nonphotosynthetic extremophiles. We pair the HWO telescope model to a 1-D radiative transfer model to estimate the required exposure times necessary for detecting each biosignature on planets with global microbial coverage and varying atmospheric water vapor concentrations. For modeled planets with 0% - 50% cloud coverage, we determine pigments and the red edge could be detected within 1,000 hours (100 hours) at distances within 15 pc (11 pc). However, tighter telescope inner working angles (2.5 lambda/D) would allow surface biosignature detection at further distances. Anoxygenic photosynthetic biosignatures could also be more easily detectable than nonphotosynthetic pigments and the photosynthetic red edge when compared against a false positive iron oxide slope. Future life detection missions should evaluate the influence of false positives on the detection of multiple surface biosignatures.
title Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2404.16126