The prospect of alien life in exotic forms on other worlds
Abstract
The nature of life on Earth provides a singular example of carbon-based, water-borne, photosynthesis-driven biology. Within our understanding of chemistry and the physical laws governing the universe, however, lies the possibility that alien life could be based on different chemistries, solvents, and energy sources from the one example provided by Terran biology. In this paper, we review some of these possibilities. Silanes may be used as functional analogs to carbon molecules in environments very different from Earth; solvents other than water may be compatible for life-supporting processes, especially in cold environments, and a variety of energy sources may be utilized, some of which have no Terran analog. We provide a detailed discussion of two possible habitats for alien life which are generally not considered as such: the lower cloud level of the Venusian atmosphere and Titan's surface environment.
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Alternative solvents to water include sulfuric acid, ammonia, methane, ethane, and nitrogen, each of which would be stable at the surface for different star-planet orbiting distances.
“Alternative solvents include sulfuric acid, ammonia, methane, ethane, nitrogen, each of which would be stable at the surface for different star-planet orbiting distances.”
From The Astrobiology Primer v2.0 (2016) · cites this paper as Schulze-Makuch and Irwin, 2006
Cites
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“Microbial colonization occurs in cryoconite holes on glaciers (Wharton et al. 1985) and in basal glacial melt waters, some of which are known to release methane as a metabolic end product (Campen et al. 2003; Souchez et al. 1995).”
BackgroundMonod, J. (1974) · Studies in the Philosophy of Biology · doi:10.1007/978-1-349-01892-5_20 · Cited by 967 · see citing works
Is there a common chemical model for life in the universe?
Benner, S. A., Ricardo, A., & Carrigan, M. A. (2004) · Current Opinion in Chemical Biology · doi:10.1016/j.cbpa.2004.10.003 · Cited by 363 · see citing works
Many Chemistries Could Be Used to Build Living Systems
Bains, W. (2004) · Astrobiology · doi:10.1089/153110704323175124 · Cited by 193 · see citing works
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Thermal Energy and the Origin of Life
Muller, A. W. J., & Schulze-Makuch, D. (2006) · Origins of Life and Evolution of Biospheres · doi:10.1007/s11084-005-9003-4 · Cited by 40 · see citing works
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Domagal-Goldman, S. D., Wright, K. E., Domagal-Goldman, S. D., Wright, K. E., Adamala, K., Arina de la Rubia, L., Bond, J., Dartnell, L. R., Goldman, A. D., Lynch, K., et al. (2016) · Astrobiology · doi:10.1089/ast.2015.1460 · Cited by 136 · see citing works
“…solvents to water might be used, and in what environments, is still debated within the astrobiology community, although the view of many is still that liquid water is an essential condition for life (Bains, 2004; Benner et al., 2004; Schulze-Makuch and Irwin, 2006; Ward and Benner, 2007).”
Hidden Concepts in the History and Philosophy of Origins-of-Life Studies: A Workshop Report
Mariscal, C., Barahona, A., Aubert-Kato, N., Aydinoglu, A. U., Bartlett, S., Cárdenas, M. L., Chandru, K., Cleland, C., Cocanougher, B. T., Comfort, N., et al. (2019) · Origins of Life and Evolution of Biospheres · doi:10.1007/s11084-019-09580-x · Cited by 36 · see citing works
Pluralism or unity in biology: could microbes hold the secret to life?
Cleland, C. E. (2013) · Biology & Philosophy · doi:10.1007/s10539-013-9361-7 · Cited by 6 · see citing works
- Authors
- Schulze-Makuch, D., & Irwin, L. N.
- Affiliations
- The University of Texas at El Paso (US)
- ORCID
- Irwin, Louis N.
- Venue
- Naturwissenschaften
- Published
- 2006-03-09
- Volume
- 93
- Issue
- 4
- Pages
- 155-172
- ISSN
- 0028-1042 (ISSN-L)
- 1432-1904
- OpenAlex
- W2088079980
- Cited by
- 125
- References
- 6
- Citations by year
- 2026: 4 · 2025: 11 · 2024: 8 · 2023: 4 · 2022: 4 · 2021: 2 · 2020: 7 · 2019: 19 · 2018: 13 · 2017: 5 · 2016: 4 · 2015: 6 · 2014: 5 · 2013: 7 · 2012: 2
- FWCI
- 0.38
- Type
- journal article
- Language
- en
- Open access
- closed
- Licence
- www.springer.com/tdm (tdm)
- Locations
- Die Naturwissenschaften (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Space Science and Extraterrestrial Life
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Origins and Evolution of Life
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Planetary Science and Exploration
- Keywords
- extraterrestrial life, alternative biochemistry, silane, non-aqueous solvents, alternative energy, Venus atmosphere, Titan, habitability, extremophiles, photosynthesis
- MeSH terms
- Carbon, Environment, Photosynthesis, Silicon, Water, Planets, Earth, Planet, Exobiology, Life
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