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Extraterrestrial life, colloquially referred to as alien life, is life that may occur outside of Earth and which did not originate on Earth. No extraterrestrial life has yet been conclusively detected, although efforts are underway. Such life might range from simple forms like prokaryotes to intelligent beings, possibly bringing forth civilizations that might be far more advanced than humankind. The Drake equation speculates about the existence of sapient life elsewhere in the universe. The science of extraterrestrial life is known as astrobiology.
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Planetary oceanography also called astro-oceanography or exo-oceanography is the study of oceans on planets and moons other than Earth. Unlike other planetary sciences like astrobiology, astrochemistry and planetary geology, it only began after the discovery of underground oceans in Saturn's moon Titan and Jupiter's moon Europa. This field remains speculative until further missions reach the oceans beneath the rock or ice layer of the moons. There are many theories about oceans or even ocean worlds of celestial bodies in the Solar System, from oceans made of diamond in Neptune to a gigantic ocean of liquid hydrogen that may exist underneath Jupiter's surface.
References
- 1 2 Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm
- 1 2 Committee on the Limits of Organic Life in Planetary Systems, Committee on the Origins and Evolution of Life, National Research Council. The Limits of Organic Life in Planetary Systems. National Academies Press (2007)
- ↑ Isaac Asimov, The Thalassogens, The Magazine of Fantasy and Science Fiction, December 1970, ed. Edward L. Ferman, publ. Mercury Press, Inc., $0.60,
- ↑ Isaac Asimov, The Left Hand of the Electron, Doubleday, 0-385-04345-7, 225pp, 1972
- ↑ Bains, William (June 2004). "Many chemistries could be used to build living systems". Astrobiology. 4 (2): 137–67. Bibcode:2004AsBio...4..137B. doi:10.1089/153110704323175124. PMID 15253836.