Photosynthesis in Hydrogen-Dominated Atmospheres
The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-...
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| Format: | Article |
| Language: | en_US |
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MDPI AG
2015
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| Online Access: | http://hdl.handle.net/1721.1/97912 https://orcid.org/0000-0002-6892-6948 |
| _version_ | 1826194913520254976 |
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| author | Bains, William Seager, Sara Zsom, Andras |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Bains, William Seager, Sara Zsom, Andras |
| author_sort | Bains, William |
| collection | MIT |
| description | The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H[subscript 2]-dominated atmosphere. If a rocky, H[subscript 2]-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH[subscript 4]-based photosynthesis as compared with CO[subscript 2]-based photosynthesis. We find that a by-product biosignature gas is likely to be H[subscript 2], which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life. |
| first_indexed | 2024-09-23T10:03:49Z |
| format | Article |
| id | mit-1721.1/97912 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:03:49Z |
| publishDate | 2015 |
| publisher | MDPI AG |
| record_format | dspace |
| spelling | mit-1721.1/979122022-09-30T18:38:21Z Photosynthesis in Hydrogen-Dominated Atmospheres Bains, William Seager, Sara Zsom, Andras Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Department of Physics Bains, William Seager, Sara Zsom, Andras The diversity of extrasolar planets discovered in the last decade shows that we should not be constrained to look for life in environments similar to early or present-day Earth. Super-Earth exoplanets are being discovered with increasing frequency, and some will be able to retain a stable, hydrogen-dominated atmosphere. We explore the possibilities for photosynthesis on a rocky planet with a thin H[subscript 2]-dominated atmosphere. If a rocky, H[subscript 2]-dominated planet harbors life, then that life is likely to convert atmospheric carbon into methane. Outgassing may also build an atmosphere in which methane is the principal carbon species. We describe the possible chemical routes for photosynthesis starting from methane and show that less energy and lower energy photons could drive CH[subscript 4]-based photosynthesis as compared with CO[subscript 2]-based photosynthesis. We find that a by-product biosignature gas is likely to be H[subscript 2], which is not distinct from the hydrogen already present in the environment. Ammonia is a potential biosignature gas of hydrogenic photosynthesis that is unlikely to be generated abiologically. We suggest that the evolution of methane-based photosynthesis is at least as likely as the evolution of anoxygenic photosynthesis on Earth and may support the evolution of complex life. 2015-07-29T12:16:29Z 2015-07-29T12:16:29Z 2014-11 2014-10 Article http://purl.org/eprint/type/JournalArticle 2075-1729 http://hdl.handle.net/1721.1/97912 Bains, William, Sara Seager, and Andras Zsom. “Photosynthesis in Hydrogen-Dominated Atmospheres.” Life 4, no. 4 (November 18, 2014): 716–744. https://orcid.org/0000-0002-6892-6948 en_US http://dx.doi.org/10.3390/life4040716 Life Creative Commons Attribution http://creativecommons.org/licenses/by/4.0/ application/pdf MDPI AG Life (Basel) |
| spellingShingle | Bains, William Seager, Sara Zsom, Andras Photosynthesis in Hydrogen-Dominated Atmospheres |
| title | Photosynthesis in Hydrogen-Dominated Atmospheres |
| title_full | Photosynthesis in Hydrogen-Dominated Atmospheres |
| title_fullStr | Photosynthesis in Hydrogen-Dominated Atmospheres |
| title_full_unstemmed | Photosynthesis in Hydrogen-Dominated Atmospheres |
| title_short | Photosynthesis in Hydrogen-Dominated Atmospheres |
| title_sort | photosynthesis in hydrogen dominated atmospheres |
| url | http://hdl.handle.net/1721.1/97912 https://orcid.org/0000-0002-6892-6948 |
| work_keys_str_mv | AT bainswilliam photosynthesisinhydrogendominatedatmospheres AT seagersara photosynthesisinhydrogendominatedatmospheres AT zsomandras photosynthesisinhydrogendominatedatmospheres |