Illusion and reality in the atmospheres of exoplanets
The atmospheres of exoplanets reveal all their properties beyond mass, radius, and orbit. Based on bulk densities, we know that exoplanets larger than 1.5 Earth radii must have gaseous envelopes and, hence, atmospheres. We discuss contemporary techniques for characterization of exoplanetary atmosphe...
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| Format: | Article |
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American Geophysical Union (AGU)
2018
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| Online Access: | http://hdl.handle.net/1721.1/118322 https://orcid.org/0000-0002-6892-6948 |
| _version_ | 1826211654544654336 |
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| author | Deming, L. Drake Seager, Sara |
| 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 Deming, L. Drake Seager, Sara |
| author_sort | Deming, L. Drake |
| collection | MIT |
| description | The atmospheres of exoplanets reveal all their properties beyond mass, radius, and orbit. Based on bulk densities, we know that exoplanets larger than 1.5 Earth radii must have gaseous envelopes and, hence, atmospheres. We discuss contemporary techniques for characterization of exoplanetary atmospheres. The measurements are difficult, because—even in current favorable cases—the signals can be as small as 0.001% of the host star's flux. Consequently, some early results have been illusory and not confirmed by subsequent investigations. Prominent illusions to date include polarized scattered light, temperature inversions, and the existence of carbon planets. The field moves from the first tentative and often incorrect conclusions, converging to the reality of exoplanetary atmospheres. That reality is revealed using transits for close-in exoplanets and direct imaging for young or massive exoplanets in distant orbits. Several atomic and molecular constituents have now been robustly detected in exoplanets as small as Neptune. In our current observations, the effects of clouds and haze appear ubiquitous. Topics at the current frontier include the measurement of heavy element abundances in giant planets, detection of carbon-based molecules, measurement of atmospheric temperature profiles, definition of heat circulation efficiencies for tidally locked planets, and the push to detect and characterize the atmospheres of super-Earths. Future observatories for this quest include the James Webb Space Telescope and the new generation of extremely large telescopes on the ground. On a more distant horizon, NASA's study concepts for the Habitable Exoplanet Imaging Mission (HabEx) and the Large UV/Optical/Infrared Surveyor (LUVOIR) missions could extend the study of exoplanetary atmospheres to true twins of Earth. |
| first_indexed | 2024-09-23T15:09:25Z |
| format | Article |
| id | mit-1721.1/118322 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T15:09:25Z |
| publishDate | 2018 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/1183222022-09-29T13:04:43Z Illusion and reality in the atmospheres of exoplanets Deming, L. Drake Seager, Sara Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Seager, Sara The atmospheres of exoplanets reveal all their properties beyond mass, radius, and orbit. Based on bulk densities, we know that exoplanets larger than 1.5 Earth radii must have gaseous envelopes and, hence, atmospheres. We discuss contemporary techniques for characterization of exoplanetary atmospheres. The measurements are difficult, because—even in current favorable cases—the signals can be as small as 0.001% of the host star's flux. Consequently, some early results have been illusory and not confirmed by subsequent investigations. Prominent illusions to date include polarized scattered light, temperature inversions, and the existence of carbon planets. The field moves from the first tentative and often incorrect conclusions, converging to the reality of exoplanetary atmospheres. That reality is revealed using transits for close-in exoplanets and direct imaging for young or massive exoplanets in distant orbits. Several atomic and molecular constituents have now been robustly detected in exoplanets as small as Neptune. In our current observations, the effects of clouds and haze appear ubiquitous. Topics at the current frontier include the measurement of heavy element abundances in giant planets, detection of carbon-based molecules, measurement of atmospheric temperature profiles, definition of heat circulation efficiencies for tidally locked planets, and the push to detect and characterize the atmospheres of super-Earths. Future observatories for this quest include the James Webb Space Telescope and the new generation of extremely large telescopes on the ground. On a more distant horizon, NASA's study concepts for the Habitable Exoplanet Imaging Mission (HabEx) and the Large UV/Optical/Infrared Surveyor (LUVOIR) missions could extend the study of exoplanetary atmospheres to true twins of Earth. 2018-10-01T18:34:22Z 2018-10-01T18:34:22Z 2016-12 2016-12 2018-10-01T18:11:49Z Article http://purl.org/eprint/type/JournalArticle 2169-9100 http://hdl.handle.net/1721.1/118322 Deming, L. Drake, and Sara Seager. “Illusion and Reality in the Atmospheres of Exoplanets: Illusion and Reality for Exoplanets.” Journal of Geophysical Research: Planets, vol. 122, no. 1, Jan. 2017, pp. 53–75. https://orcid.org/0000-0002-6892-6948 https://doi.org/10.1002/2016JE005155 Journal of Geophysical Research: Planets Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf American Geophysical Union (AGU) arXiv |
| spellingShingle | Deming, L. Drake Seager, Sara Illusion and reality in the atmospheres of exoplanets |
| title | Illusion and reality in the atmospheres of exoplanets |
| title_full | Illusion and reality in the atmospheres of exoplanets |
| title_fullStr | Illusion and reality in the atmospheres of exoplanets |
| title_full_unstemmed | Illusion and reality in the atmospheres of exoplanets |
| title_short | Illusion and reality in the atmospheres of exoplanets |
| title_sort | illusion and reality in the atmospheres of exoplanets |
| url | http://hdl.handle.net/1721.1/118322 https://orcid.org/0000-0002-6892-6948 |
| work_keys_str_mv | AT demingldrake illusionandrealityintheatmospheresofexoplanets AT seagersara illusionandrealityintheatmospheresofexoplanets |