The prospect of alien life in exotic forms on other worlds

@article{SchulzeMakuch2005ThePO,
  title={The prospect of alien life in exotic forms on other worlds},
  author={Dirk Schulze-Makuch and Louis N. Irwin},
  journal={Naturwissenschaften},
  year={2005},
  volume={93},
  pages={155-172}
}
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… 

Figures, Tables, and Topics from this paper

The Physical, Chemical and Physiological Limits of Life
TLDR
Two specific examples are discussed: putative life on a Mars-type planet with a hydrogen peroxide-water solvent and putativelife on a Titan-type planetary body with liquid hydrocarbons as a solvent, which would have the result of extending the habitable envelope of life in the universe.
Many chemistries could be used to build living systems.
  • W. Bains
  • Chemistry, Medicine
    Astrobiology
  • 2004
TLDR
It is argued that it is the nature of the liquid in which life evolves that defines the most appropriate chemistry, and Fluids other than water could be abundant on a cosmic scale and could be an environment in which non-terrestrial biochemistry could evolve.
Oxygen-Free Biochemistry: The Putative CHN Foundation for Exotic Life in a Hydrocarbon World?
TLDR
This work hypothesizes a novel oxygen-free organic chemistry for supporting potential exotic biosystems, which is named CHN biochemistry, and theoretical calculations indicate that the energy changes of some reactions are consistent with their counterparts in Earth's biochemistry.
Epistemological issues in the study of microbial life: alternative terran biospheres?
  • Carol E. Cleland
  • Biology, Medicine
    Studies in history and philosophy of biological and biomedical sciences
  • 2007
TLDR
This paper argues that there is little theoretical or empirical support for the assumption that all life on Earth today shares the same basic molecular architecture and biochemistry, and suggests a dedicated search for 'shadow microbes' (heretofore unrecognized 'alien' forms of terran microbial life) seems in order.
The landscape of life
Earth is a planet that exhibits an immense biomass and an incredible biodiversity. Yet, the question arises as to whether the diversity as observed on Earth reflects the limits of life or whether
Physicochemical Requirements Inferred for Chemical Self-Organization Hardly Support an Emergence of Life in the Deep Oceans of Icy Moons.
  • R. Pascal
  • Environmental Science, Medicine
    Astrobiology
  • 2016
TLDR
The possibility of the emergence of life in the hydrothermal systems possibly present in the deep oceans below the frozen crust of some of the moons of Jupiter and Saturn has been raised and the mutual compatibility of alternative views is investigated.
Drastic environmental change and its effects on a planetary biosphere
Environmental conditions can change drastically and rapidly during the natural history of a planetary body. These changes affect the biosphere and can spur evolution via the mechanism of directional
The Future and Fate of Living Systems
The future of life on Earth and elsewhere in the Universe is the least studied of the three fundamental questions posed by NASA’s Astrobiology Roadmap (Des Marais and Walter 1999; Des Marais et al.
Chance and necessity in biochemistry: implications for the search for extraterrestrial biomarkers in Earth-like environments.
TLDR
It is predicted that life originating in extraterrestrial Earth-like environments will share biochemical motifs that can be traced back to the prebiotic world but will also have intrinsic biochemical traits that are unlikely to be duplicated elsewhere as they are combinatorially path-dependent.
The search for alien life in our solar system: strategies and priorities.
TLDR
It is judged that an intensive investigation of a small number of bodies in the authors' Solar System is more likely to succeed than a broad-based survey of a great number of worlds.
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 148 REFERENCES
A sulfur-based survival strategy for putative phototrophic life in the venusian atmosphere.
TLDR
It is made the argument that such an organism may utilize sulfur allotropes present in the venusian atmosphere, particularly S(8), as a UV sunscreen, as an energy-converting pigment, or as a means for converting UV light to lower frequencies that can be used for photosynthesis.
Many chemistries could be used to build living systems.
  • W. Bains
  • Chemistry, Medicine
    Astrobiology
  • 2004
TLDR
It is argued that it is the nature of the liquid in which life evolves that defines the most appropriate chemistry, and Fluids other than water could be abundant on a cosmic scale and could be an environment in which non-terrestrial biochemistry could evolve.
Life on venus
Abstract A fundamental question in exobiology remains the degree to which habitats on Venus, past and present, were, or are suitable for life. This has relevance for assessing the exobiological
An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent.
TLDR
This work describes the isolation and cultivation of a previously unknown green sulfur bacterial species from a deep-sea hydrothermal vent, where the only source of light is geothermal radiation that includes wavelengths absorbed by photosynthetic pigments of this organism.
Exobiological Implications of a Possible Ammonia–Water Ocean inside Titan
Models of Titan's thermal history indicate that an ocean consisting of an ammonia-water solution, as much as 200 km deep, is presently concealed beneath a crust of water ice. Conditions within this
Thermal Energy and the Origin of Life
TLDR
It has been proposed that the first organisms obtained their energy by a first protein named pF1 that worked on a thermal variation of the binding change mechanism of today's ATP sythase enzyme.
Possibilities for methanogenic life in liquid methane on the surface of Titan
Photochemically produced compounds on Titan, principally acetylene, ethane and organic solids, would release energy when consumed with atmospheric hydrogen, at levels of 334, 57, and 54 kJ mol −1 ,
Energy cycling and hypothetical organisms in Europa's ocean.
TLDR
Using reasonable assumptions based on known organisms on Earth, these calculations suggest that chemical oxidation-reduction cycles in Europa's subsurface ocean could support life.
Is there a common chemical model for life in the universe
A review of organic chemistry suggests that life, a chemical system capable of Darwinian evolution, may exist in a wide range of environments. These include non-aqueous solvent systems at low
Clay minerals and the origin of life
This volume is the edited proceedings of a conference seeking to clarify the possible role of clays in the origin of life on Earth. At the heart of the problem of the origin of life lie fundamental
...
1
2
3
4
5
...