scholarly journals Commission 51: Search for Extraterrestrial Life

1985 ◽  
Vol 19 (1) ◽  
pp. 713-723
Author(s):  
M. D. Papagiannis ◽  
F. D. Drake ◽  
N. S. Kardashev ◽  
R. D. Brown ◽  
P. Connes ◽  
...  
Keyword(s):  
Experimental Techniques ◽  
Extraterrestrial Life ◽  
Origin And Evolution ◽  
Whole Process ◽  
Cosmic Evolution ◽  
Lay People ◽  
The Universe

The possibility that life, primitive or advanced, might exist in other places of the Universe has occupied the minds of scientists and lay-people for thousands of years. It is only in the last 25 years, however, that we have finally begun to search for answers to this profound question using experimental techniques. The goal of Astronomy is to understand the origin and evolution of planets, stars, galaxies and of the Universe as a whole. The appearance of life is an integral part of this whole process and our picture of the Universe will never be complete until we will comprehend also the significance of life in the process of Cosmic Evolution.

Search for Life in the Universe with terrestrial microbes which Thrive under Extreme Conditions

1997 ◽  
Vol 161 ◽  
pp. 511-523 ◽  
Author(s):  
Joseph Seckbach
Keyword(s):  
Hot Spring ◽  
Life Forms ◽  
Growth Conditions ◽  
Eukaryotic Cell ◽  
Extraterrestrial Life ◽  
Origin And Evolution ◽  
Algal Group ◽  
Living Organisms ◽  
The Many ◽  
The Universe

AbstractIt is reasonable to believe that life exists in many places throughout the Universe. Among the many billions of heavenly bodies, there are galaxies with millions of stars that may harbor lower or even higher forms of living organisms («life» in the meaning as we know it, e.g., carbon chemistry, liquid water etc.). This article lists Extremophiles and their various terrestrial enigmatic environments. We discuss the possibilities of Martian life and the origin and evolution of the eukaryotic cell and present some early protists and the Acidothermophilic algae. Among several microbes which can «fit» for extraterrestrial life, one eukaryotic algal group (Cyanidiophyceae) is treated here. The hot springCyanidium caldariummembers (there are three genera and several species in this family) thrive in excessive growth conditions like in acidic medium (close to IN H2SO4), under pure CO2atmosphere, in elevated temperature and auto or heterotrophic conditions. These hot spring unicellular algae do not require oxygen for such conditions of growth. Studies have shown that they present one of the earliest and simplest eukaryotic algae. Also, these microbes may be candidates for existing on planets with similar ecological conditions which might support life forms.

Cultural evolution, the postbiological universe and SETI

2003 ◽  
Vol 2 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Steven J. Dick
Keyword(s):  
Cultural Evolution ◽  
Biological Evolution ◽  
General Nature ◽  
Extraterrestrial Life ◽  
Cosmic Evolution ◽  
History Of ◽  
The Subject ◽  
The Universe ◽  
Biological Universe

The Biological Universe (Dick 1996) analysed the history of the extraterrestrial life debate, documenting how scientists have assessed the chances of life beyond Earth during the 20th century. Here I propose another option – that we may in fact live in a postbiological universe, one that has evolved beyond flesh and blood intelligence to artificial intelligence that is a product of cultural rather than biological evolution. MacGowan & Ordway (1966), Davies (1995) and Shostak (1998), among others, have broached the subject, but the argument has not been given the attention it is due, nor has it been carried to its logical conclusion. This paper argues for the necessity of long-term thinking when contemplating the problem of intelligence in the universe. It provides arguments for a postbiological universe, based on the likely age and lifetimes of technological civilizations and the overriding importance of cultural evolution as an element of cosmic evolution. And it describes the general nature of a postbiological universe and its implications for the search for extraterrestrial intelligence.

scholarly journals On the origin and evolution of life in the Galaxy

2010 ◽  
Vol 9 (4) ◽  
pp. 217-226 ◽  
Author(s):  
Michael McCabe ◽  
Holly Lucas
Keyword(s):  
Extraterrestrial Life ◽  
Evolutionary Transitions ◽  
Origin And Evolution ◽  
A Value ◽  
Evolution Of Life ◽  
Life On Mars ◽  
The Galaxy ◽  
The Origin Of Life ◽  
The Universe ◽  
Present Understanding

AbstractA simple stochastic model for evolution, based upon the need to pass a sequence of n critical steps is applied to both terrestrial and extraterrestrial origins of life. In the former case, the time at which humans have emerged during the habitable period of Earth suggests a value of n=4. Progressively adding earlier evolutionary transitions gives an optimum fit when n=5, implying either that their initial transitions are not critical or that habitability began around 6 Ga ago. The origin of life on Mars or elsewhere within the Solar System is excluded by the latter case and the simple anthropic argument is that extraterrestrial life is scarce in the Universe because it does not have time to evolve. Alternatively, the timescale can be extended if the migration of basic progenotic material to Earth is possible. If extra transitions are included in the model to allow for Earth migration, then the start of habitability needs to be even earlier than 6 Ga ago. Our present understanding of Galactic habitability and dynamics does not exclude this possibility. We conclude that Galactic punctuated equilibrium, proposed as a way round the anthropic problem, is not the only way of making life more common in the Galaxy.

The Cosmic Mystery Tour

2019 ◽  
Author(s):  
Nicholas Mee
Keyword(s):  
Science Fiction ◽  
Particle Physics ◽  
Cultural Context ◽  
Big Bang ◽  
Galactic Centre ◽  
Red Giants ◽  
Extraterrestrial Life ◽  
Modern Physics ◽  
Recent Developments ◽  
The Universe

The Cosmic Mystery Tour is a brief account of modern physics and astronomy presented in a broad historical and cultural context. The book is attractively illustrated and aimed at the general reader. Part I explores the laws of physics including general relativity, the structure of matter, quantum mechanics and the Standard Model of particle physics. It discusses recent discoveries such as gravitational waves and the project to construct LISA, a space-based gravitational wave detector, as well as unresolved issues such as the nature of dark matter. Part II begins by considering cosmology, the study of the universe as a whole and how we arrived at the theory of the Big Bang and the expanding universe. It looks at the remarkable objects within the universe such as red giants, white dwarfs, neutron stars and black holes, and considers the expected discoveries from new telescopes such as the Extremely Large Telescope in Chile, and the Event Horizon Telescope, currently aiming to image the supermassive black hole at the galactic centre. Part III considers the possibility of finding extraterrestrial life, from the speculations of science fiction authors to the ongoing search for alien civilizations known as SETI. Recent developments are discussed: space probes to the satellites of Jupiter and Saturn; the discovery of planets in other star systems; the citizen science project SETI@Home; Breakthrough Starshot, the project to develop technologies to send spacecraft to the stars. It also discusses the Fermi paradox which argues that we might actually be alone in the cosmos

scholarly journals LARGE SCALE ANISOTROPY DUE TO PRE-INFLATIONARY PHASE OF COSMIC EVOLUTION

2012 ◽  
Vol 27 (04) ◽  
pp. 1250014 ◽  
Author(s):  
PAVAN K. ALURI ◽  
PANKAJ JAIN
Keyword(s):  
Large Scale ◽  
Cosmological Evolution ◽  
Cosmic Evolution ◽  
Cosmological Observations ◽  
Inflationary Phase ◽  
The Universe ◽  
Dipole Modulation

We show that perturbations generated during the anisotropic pre-inflationary stage of cosmic evolution may affect cosmological observations today for a certain range of parameters. Due to the anisotropic nature of the universe during such early times, it might explain some of the observed signals of large scale anisotropy. In particular, we argue that the alignment of CMB quadrupole and octopole may be explained by the Sachs–Wolfe effect due to the large scale anisotropic modes from very early times of cosmological evolution. We also comment on how the observed dipole modulation of CMB power may be explained within this framework.

On the parallels between cosmology and astrobiology: a transdisciplinary approach to the search for extraterrestrial life

2016 ◽  
Vol 15 (4) ◽  
pp. 251-260 ◽  
Author(s):  
Charles Morphy D. Santos ◽  
Leticia P. Alabi ◽  
Amâncio C. S. Friaça ◽  
Douglas Galante
Keyword(s):  
Extraterrestrial Life ◽  
Transdisciplinary Approach ◽  
Research Areas ◽  
Copernican Revolution ◽  
Scientific Status ◽  
Intrinsic Complexity ◽  
Experimental Approaches ◽  
The Universe

AbstractThe establishment of cosmology as a science provides a parallel to the building-up of the scientific status of astrobiology. The rise of astrobiological studies is explicitly based on a transdisciplinary approach that reminds of the Copernican Revolution, which eroded the basis of a closed Aristotelian worldview and reinforced the notion that the frontiers between disciplines are artificial. Given the intrinsic complexity of the astrobiological studies, with its multifactorial evidences and theoretical/experimental approaches, multi- and interdisciplinary perspectives are mandatory. Insulated expertise cannot grasp the vastness of the astrobiological issues. This need for integration among disciplines and research areas is antagonistic to excessive specialization and compartmentalization, allowing astrobiology to be qualified as a truly transdisciplinary enterprise. The present paper discusses the scientific status of astrobiological studies, based on the view that every kind of life, Earth-based or not, should be considered in a cosmic context. A confluence between ‘astro’ and ‘bio’ seeks the understanding of life as an emerging phenomenon in the universe. Thus, a new epistemological niche is opened, pointing to the development of a pluralistic vision for the philosophy of astrobiology.

scholarly journals The Molecular Universe

2011 ◽  
Vol 7 (S280) ◽  
pp. 3-18 ◽  
Author(s):  
A. G. G. M. Tielens
Keyword(s):  
Planet Formation ◽  
Chemical Processes ◽  
Complex Species ◽  
Origin And Evolution ◽  
Physical Conditions ◽  
Evolution Of Galaxies ◽  
Fundamental Goal ◽  
Molecular Complexity ◽  
The Universe

AbstractOver the last 20 years, we have discovered that we live in a molecular Universe: A Universe with a rich and varied organic inventory; A Universe where molecules are abundant and widespread; A Universe where molecules play a central role in key processes that dominate the structure and evolution of galaxies; A Universe where molecules provide convenient thermometers and barometers to probe local physical conditions; A Universe where molecules can work together to form such complex species as you and me. Understanding the origin and evolution of interstellar and circumstellar molecules is thus key to understanding the Universe around us and our place in it and has become a fundamental goal of modern astrophysics. This review focuses on the organic inventory and the chemical processes that may play a role in stablishing molecular complexity in regions of planet formation.

Does extraterrestrial life have intrinsic value? An exploration in responsibility ethics

2018 ◽  
Vol 18 (4) ◽  
pp. 304-310 ◽  
Author(s):  
Ted Peters
Keyword(s):  
Intrinsic Value ◽  
Naturalistic Fallacy ◽  
Moral Norm ◽  
Extraterrestrial Life ◽  
Responsibility Ethics ◽  
The Universe ◽  
Ethical Quandary

AbstractIf space explorers discover a biosphere supporting life on an off-Earth body, should they treat that life as possessing intrinsic value? This is an ethical quandary leading to a further question: how do we ground a universal moral norm to which the astroethicist can appeal? This article closely analyses various forms of responsibility ethics and finds them weak because they commit the naturalistic fallacy – that is, they ask nature to definethe good. The good, however, is self-defining and not derivable from nature. Even so, a revised responsibility ethic could ground its universal norms on the fact that life and only life can experience and appreciate the good. Conclusion: living creatures possess intrinsic value both on Earth and elsewhere in the Universe.

scholarly journals Life under another Sun: From Science Fiction to Science

2019 ◽  
Vol 28 (1) ◽  
pp. 18-39
Author(s):  
Michaël Gillon
Keyword(s):  
Twentieth Century ◽  
Sixteenth Century ◽  
Science Fiction ◽  
Paradigm Shift ◽  
Life Science ◽  
Technological Development ◽  
Major Theme ◽  
Extraterrestrial Life ◽  
Copernican Revolution ◽  
The Universe

Initiated in the sixteenth century, the Copernican revolution toppled our Earth from its theological pedestal, revealing it not to be the centre of everything but a planet among several others in orbit around one of the zillions of stars of our Universe. Already proposed by some philosophers at the dawn of this major paradigm shift, the existence of exoplanets, i.e. planets in orbit around stars other than our Sun, remained suspected but unconfirmed for centuries. It is only in the last decade of the twentieth century that the first of these extrasolar worlds were found. Their seminal discoveries initiated the development of more and more ambitious projects that led eventually to the detection of thousands of exoplanets, including a few dozen potentially habitable ones, i.e. terrestrial exoplanets that could harbour large amounts of liquid water – and maybe life – on their surfaces. Upcoming astronomical facilities will soon be able to probe the atmospheric compositions of some of these extrasolar worlds, maybe performing in the process the historical detection of chemical signs of life light-years away. But while the existence of extraterrestrial life remains pure speculation for now, it has been a major theme of science fiction for more than a century. By creating countless stories of encounters between humans and alien forms of life, science-fiction authors have pursued, in a sense, the Copernican revolution, confronting us with the idea that not only could life be widespread in the Universe, but also that our species may be far from the Cosmic pinnacle in matters of intelligence and technological development.

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