Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions
In the near-future, atmospheric characterization of Earth-like planets in the habitable zone will become possible via reflectance spectroscopy with future telescopes such as the proposed LUVOIR and HabEx missions. While previous studies have considered the effect of clouds on the reflectance spectra...
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| Format: | Journal article |
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American Astronomical Society
2019
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| _version_ | 1797090942332698624 |
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| author | Macgregor, S Kawashima, Y |
| author_facet | Macgregor, S Kawashima, Y |
| author_sort | Macgregor, S |
| collection | OXFORD |
| description | In the near-future, atmospheric characterization of Earth-like planets in the habitable zone will become possible via reflectance spectroscopy with future telescopes such as the proposed LUVOIR and HabEx missions. While previous studies have considered the effect of clouds on the reflectance spectra of Earth-like planets, the molecular detectability considering a wide range of cloud properties has not been previously explored in detail. In this study, we explore the effect of cloud altitude and coverage on the reflectance spectra of Earth-like planets at different geological epochs and examine the detectability of ${{\rm{O}}}_{2},{{\rm{H}}}_{2}{\rm{O}}$, and CH4 with test parameters for the future mission concept, LUVOIR, using a coronagraph noise simulator previously designed for WFIRST-AFTA. Considering an Earth-like planet located at 5 pc away, we have found that for the proposed LUVOIR telescope, the detection of the O2 A-band feature (0.76 μm) will take approximately 100, 30, and 10 hr for the majority of the cloud parameter space modeled for the atmospheres with 10%, 50%, and 100% of modern Earth O2 abundances, respectively. In particular, for the case of ≥50% of modern Earth O2 abundance, the feature will be detectable with an integration time ≤10 hr as long as there are lower-altitude (≤8 km) clouds with a global coverage of ≥20%. For the 1% of the modern Earth O2 abundance case, however, it will take more than 100 hr for all the cloud parameters we modeled. |
| first_indexed | 2024-03-07T03:25:54Z |
| format | Journal article |
| id | oxford-uuid:b9050fb4-dff3-4b93-9b9e-5d50fbe2440c |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:25:54Z |
| publishDate | 2019 |
| publisher | American Astronomical Society |
| record_format | dspace |
| spelling | oxford-uuid:b9050fb4-dff3-4b93-9b9e-5d50fbe2440c2022-03-27T05:00:09ZTheoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missionsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b9050fb4-dff3-4b93-9b9e-5d50fbe2440cSymplectic Elements at OxfordAmerican Astronomical Society2019Macgregor, SKawashima, YIn the near-future, atmospheric characterization of Earth-like planets in the habitable zone will become possible via reflectance spectroscopy with future telescopes such as the proposed LUVOIR and HabEx missions. While previous studies have considered the effect of clouds on the reflectance spectra of Earth-like planets, the molecular detectability considering a wide range of cloud properties has not been previously explored in detail. In this study, we explore the effect of cloud altitude and coverage on the reflectance spectra of Earth-like planets at different geological epochs and examine the detectability of ${{\rm{O}}}_{2},{{\rm{H}}}_{2}{\rm{O}}$, and CH4 with test parameters for the future mission concept, LUVOIR, using a coronagraph noise simulator previously designed for WFIRST-AFTA. Considering an Earth-like planet located at 5 pc away, we have found that for the proposed LUVOIR telescope, the detection of the O2 A-band feature (0.76 μm) will take approximately 100, 30, and 10 hr for the majority of the cloud parameter space modeled for the atmospheres with 10%, 50%, and 100% of modern Earth O2 abundances, respectively. In particular, for the case of ≥50% of modern Earth O2 abundance, the feature will be detectable with an integration time ≤10 hr as long as there are lower-altitude (≤8 km) clouds with a global coverage of ≥20%. For the 1% of the modern Earth O2 abundance case, however, it will take more than 100 hr for all the cloud parameters we modeled. |
| spellingShingle | Macgregor, S Kawashima, Y Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions |
| title | Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions |
| title_full | Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions |
| title_fullStr | Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions |
| title_full_unstemmed | Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions |
| title_short | Theoretical reflectance spectra of Earth-like planets through their evolutions: impact of clouds on the detectability of oxygen, water, and methane with future direct imaging missions |
| title_sort | theoretical reflectance spectra of earth like planets through their evolutions impact of clouds on the detectability of oxygen water and methane with future direct imaging missions |
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