The DOI matches its Crossref record; 27 of the 28 references it cites were found in a registry or an index.
A search for life on Earth from the Galileo spacecraft
Abstract
In its December 1990 fly-by of Earth, the Galileo spacecraft found evidence of abundant gaseous oxygen, a widely distributed surface pigment with a sharp absorption edge in the red part of the visible spectrum, and atmospheric methane in extreme thermodynamic disequilibrium; together, these are strongly suggestive of life on Earth. Moreover, the presence of narrow-band, pulsed, amplitude-modulated radio transmission seems uniquely attributable to intelligence. These observations constitute a control experiment for the serach for extraterrestrial life by modern interplanetary spacecraft.
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In the citing paper
“Moreover, the detection of both, a classic disequilibrium biosignature (e.g., Sagan et al., 1993), would have been lost to observers.”
From Oxygenation, Life, and the Planetary System during Earth's Middle History: An Overview (2021) · cites this paper as Sagan et al., 1993
In the citing paper
“The Galileo spacecraft, when doing a flyby of Earth, demonstrated that this disequilibrium could be remotely detected via spectroscopy of the atmosphere of the planet; this is similar to plans to detect this disequilibrium on potentially habitable extrasolar planets (Sagan et al., 1993; see also Section 7.2.2).”
From The Astrobiology Primer v2.0 (2016) · cites this paper as Sagan et al., 1993
In the citing paper
“Atmospheric species such as oxygen and methane (and other reduced gases) should not coexist in appreciable quantities in an equilibrium atmosphere (Lovelock, 1965; Sagan et al., 1993), yet they do on our living planet.”
From The Astrobiology Primer v2.0 (2016) · cites this paper as Sagan et al., 1993
In the citing paper
“A more general biosignature, which has not been considered for the early Earth, is atmospheric chemical disequilibrium, evident in the coexistence of two or more long-term incompatible gases (17–20).”
From Disequilibrium biosignatures over Earth history and implications for detecting exoplanet life (2018) · cites this paper as [20]
Citations
Cites
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Self-citation
Flagged first, then by citations
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Research works printed but not linked: 9
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Biogeochemical Controls and Feedbacks on Ocean Primary Production
Falkowski, P. G., Barber, R. T., & Smetacek, V. (1998) · Science · doi:10.1126/science.281.5374.200 · Cited by 2,848
Anaerobic Metabolism: Linkages to Trace Gases and Aerobic Processes
Megonigal, J. P., Hines, M. E., & Visscher, P. T. (2003) · Elsevier eBooks · doi:10.1016/b0-08-043751-6/08132-9 · Cited by 599
Remote Sensing of Planetary Properties and Biosignatures on Extrasolar Terrestrial Planets
Marais, D. J. D., Harwit, M. O., Jucks, K. W., Kasting, J. F., Lin, D. N. C., Lunine, J. I., Schneider, J. L., Seager, S., Traub, W. A., & WOOLF, N. J. (2002) · Astrobiology · doi:10.1089/15311070260192246 · Cited by 540
Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life
Schwieterman, E. W., Kiang, N. Y., Parenteau, M. N., Harman, C. E., DasSarma, S., Fisher, T. M., Arney, G. N., Hartnett, H. E., Reinhard, C. T., Olson, S. L., et al. (2018) · Astrobiology · doi:10.1089/ast.2017.1729 · Cited by 630
Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life
Schwieterman, E. W., Kiang, N. Y.-L., Parenteau, M. N., Harman, C. E., DasSarma, S., Fisher, T. M., Arney, G., Hartnett, H. E., Reinhard, C. T., Olson, S. L., et al. (2017) · eScholarship (California Digital Library) · Cited by 452
Metadata
- Authors
- Sagan, C., Thompson, W. R., Carlson, R., Gurnett, D., & Hord, C.
- Affiliations
- Cornell University (US)
- Jet Propulsion Laboratory (US)
- University of Iowa (US)
- University of Colorado Boulder (US)
- Venue
- Nature
- Published
- 1993-10
- Volume
- 365
- Issue
- 6448
- Pages
- 715-721
- ISSN
- 0028-0836 (ISSN-L)
- 1476-4687
- OpenAlex
- W1972716255
- Cited by
- 507
- References
- 28
- Citations by year
- 2026: 14 · 2025: 26 · 2024: 25 · 2023: 47 · 2022: 13 · 2021: 28 · 2020: 19 · 2019: 51 · 2018: 57 · 2017: 19 · 2016: 11 · 2015: 11 · 2014: 10 · 2013: 14 · 2012: 11
- FWCI
- 6.61
- Type
- journal article
- Language
- en
- Open access
- closed
- Licence
- www.springer.com/tdm (tdm)
- Locations
- Nature (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Space Science and Extraterrestrial Life
- Physical Sciences › Earth and Planetary Sciences › Space and Planetary Science › Planetary Science and Exploration
- Physical Sciences › Environmental Science › Global and Planetary Change › Earth Systems and Cosmic Evolution
- Keywords
- Galileo spacecraft, gaseous oxygen, atmospheric methane, thermodynamic non-equilibrium, radio transmission, extraterrestrial life detection, interplanetary spacecraft, planetary atmospheres
- MeSH terms
- Atmosphere, Extraterrestrial Environment, Methane, Oxygen, Radio Waves, Space Flight, Spectrophotometry, Infrared, Spectrophotometry, Ultraviolet, Water, Spacecraft, Earth, Planet, Exobiology
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