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The potential for detecting ‘life as we don't know it’ by fractal complexity analysis
- Armando Azua-Bustos, Cristian Vega-Martínez
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- Journal:
- International Journal of Astrobiology / Volume 12 / Issue 4 / October 2013
- Published online by Cambridge University Press:
- 12 June 2013, pp. 314-320
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Finding life in the Universe entirely different to the one evolved on Earth is probable. This is a significant constraint for life-detecting instruments that were sent and may be sent elsewhere in the solar system, as how could we detect life as ‘we don't know it’? How could we detect something when we have no prior knowledge of its composition or how it looks like? Here we argue that disregarding the type of lifeform that could be envisioned, all must share in common the attribute of being entities that decrease their internal entropy at the expense of free energy obtained from its surroundings. As entropy quantifies the degree of disorder in a system, any envisioned lifeform must have a higher degree of order than its supporting environment. Here, we show that by using fractal mathematics analysis alone, one can readily quantify the degree of entropy difference (and thus, their structural complexity) of living processes (lichen growths and plant growing patterns in this case) as distinct entities separate from its similar abiotic surroundings. This approach may allow possible detection of unknown forms of life based on nothing more than entropy differentials of complementary datasets. Future explorations in the solar system, like Mars or Titan, may incorporate this concept in their mission planning in order to detect potential endemic lifeforms.
8 - Early Mars – Cradle or Cauldron?
- from Part IV - Habitability of the Solar System
- Edited by Chris Impey, University of Arizona, Jonathan Lunine, Cornell University, New York, José Funes, Vatican Observatory, Vatican City
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- Book:
- Frontiers of Astrobiology
- Published online:
- 05 December 2012
- Print publication:
- 15 November 2012, pp 157-174
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Summary
Mars constitutes one of the most interesting settings for astrobiological studies, not only due to its proximity to Earth, but also because it is conceivable that life may have originated in this seemingly barren planet. Mars has captured man's imagination since the time of Giovanni Schiaparelli, who in 1877 published a detailed map that became a standard reference in planetary cartography. Schiaparelli's original map showed a network of linear markings which went across the entire Martian surface joining different dark areas to one another. He referred to these lines as canali and named them after famous rivers. The Italian word canale (plural canali) was soon incorrectly translated to English as “canals,” which denotes artificially made ducts. Being aware of this mistranslation, Schiaparelli stated that
[T]hese names may be regarded as a mere artifice…After all, we speak in a similar way of the seas of the Moon, knowing very well that they do not consist of liquid masses.
Thus, the idea of artificially made water courses remained, implying that Mars was a planet harboring life. Later on, Percival Lowell fueled further speculations about possible Martian life forms in his book Mars as the Adobe of Life (1908), popularizing the view that these markings were manifestations of an intelligent civilization.
One can analyze the possibility of life on Mars taking into consideration the different geological ages of this planet (now under revision). The Noachian period (named after Noachis Terra), which took place between 4.5 and about 3.7 billion years ago (Gya), is considered to be the warm and wet age of the planet. Extensive erosion by liquid water produced river valley networks whose marks have survived to the present time. There may even have been extensive lakes and oceans at this time, though evidence for such features is at present ambiguous. Thereafter, the Hesperian (named after Hesperia Planum) or volcanic period, from 3.7 to approximately 3.0 Gya, showed catastrophic releases of water that carved extensive outflow channels, with ephemeral lakes or seas. Finally, there is the Amazonian period (named after Amazonis Planitia), which extends from 3.0 Gya until today. It is considered the cold and dry period of Mars, with glacial/periglacial activity and minor releases of liquid water.
Mini-Review: Probing the limits of extremophilic life in extraterrestrial environment-simulated experiments
- Claudia A.S. Lage, Gabriel Z.L. Dalmaso, Lia C.R.S. Teixeira, Amanda G. Bendia, Ivan G. Paulino-Lima, Douglas Galante, Eduardo Janot-Pacheco, Ximena C. Abrevaya, Armando Azúa-Bustos, Vivian H. Pelizzari, Alexandre S. Rosado
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- Journal:
- International Journal of Astrobiology / Volume 11 / Issue 4 / October 2012
- Published online by Cambridge University Press:
- 16 August 2012, pp. 251-256
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Astrobiology is a relatively recent scientific field that seeks to understand the origin and dynamics of life in the Universe. Several hypotheses have been proposed to explain life in the cosmic context throughout human history, but only now, technology has allowed many of them to be tested. Laboratory experiments have been able to show how chemical elements essential to life, such as carbon, nitrogen, oxygen and hydrogen combine in biologically important compounds. Interestingly, these compounds are ubiquitous. How these compounds were combined to the point of originating cells and complex organisms is still to be unveiled by science. However, our 4.5 billion years old Solar system appeared in a 10 billion years old Universe. Thus, simple cells such as micro-organisms may have had time to form in planets older than ours or in other suitable places in the Universe. One hypothesis related to the appearance of life on Earth is called panspermia, which predicts that microbial life could have been formed in the Universe billions of years ago, travelling between planets, and inseminating units of life that could have become more complex in habitable planets such as Earth. A project designed to test the viability of extremophile micro-organisms exposed to simulated extraterrestrial environments is in progress at the Carlos Chagas Filho Institute of Biophysics (UFRJ, Brazil) to test whether microbial life could withstand inhospitable environments. Radiation-resistant (known or novel ones) micro-organisms collected from extreme terrestrial environments have been exposed (at synchrotron accelerators) to intense radiation sources simulating Solar radiation, capable of emitting radiation in a few hours equivalent to many years of accumulated doses. The results obtained in these experiments reveal an interesting possibility of the existence of microbial life beyond Earth.