Astrobiology/Exobiology

Understanding the physicochemical properties of biomolecules and how these properties drive the emergence of complexity in the assembly/condensation of such systems is important for a variety of reactions taking place in astrophysical environments, in particular those where polymer-ization processes occur on mineral surfaces or solid organic matter form in cold-chemistry processes. Here, a computational study of the structural and electronic properties of the gas and condensed phases of the isoleucine group of amino acids, found with large enantiomeric excess in Antarctic meteorites, is presented. An analysis of a statistical complexity measure related to their electronic properties, of the degree of chirality, and of the H-bond patterns is also reported. The results, based on Density Functional Theory, Many Body Perturbation Theory, and Møller−Plesset perturbation theory, show that a) the condensed amino acids keep reminiscence of structural and electronic properties of the gas phase molecules, b) the proteinogenic L-isoleucine gains in complexity and chirality upon condensation, contrary to its diastereomer, which is absent in living systems, and c) the complexity based on electronic properties can contrast with the notion of structural/geometrical complexity. The findings suggest that future scoring strategies of organic molecules should rely on both structural/geometrical molecular complexity and on the electronic properties, which in different states of matter are determined by other degrees of freedom (configurational or chiral) to a different extent, as well as on information storage capability of self-assembly configurations constrained by an atomistic chemistry perspective.

Gillevinia straata Crocco 2006 es una forma de vida alienígena (esto es, extraterrestre) clasificada biológicamente en diciembre de 2006. La presente nota brinda precisiones acerca del concepto, su contexto y su significación biológica. Con esa acción clasificatoria se catalogó como ser vivo a la causa de las respuestas positivas a experimentos, expresamente diseñados para descubrir seres vivos, realizados en Marte en 1975 y 1976, cuando se suponía que en ese planeta no existía agua y era completamente seco. Reaccionóse con ello al descubrimiento de agua en Marte, que sólo muy poco antes había sido confirmado (en junio de 2006; luego se supo que Marte tiene tanto hielo de agua que, de haber sido líquido, cubriría todo el planeta con un océano de 35 metros de profundidad; en agosto de 2018 el radar evidenció bajo el hielo polar un lago atrapado de agua líquida, probablemente salobre, de 20 km de ancho 5 , y en junio de 2018 se verificó directamente 6 que unos 3500 millones de años atrás había existido materia orgánica en ese planeta), y al hallazgo de oscilaciones con duración de un día, llamadas ciclos circadianos, en los registros de la suelta o liberación de gases marcados ("Labeled release") en nueve experimentos que duraron hasta nueve meses cada uno.

Alejandro Stern integra el Equipo de Políticas Públicas de Salud de la Convención Nacional del partido político Unión Cívica Radical, República Argentina.

It is no science fiction, No star wars, or 2012, If you have seen these films and movies; image the possibilities of living in an extra-terrestrial world.  Yes the reality is closer as space exploration, human evolution, existence and astrobiology is answering the possibilities of living on mars.

The use of symbols in Fraternal lodges, esoteric groups and society is held in common. They differ in the shared values of these symbols. Part of this is likely due to time depth shared in liminal space with these symbol sets within the context of the motifs and stories held in common and developed in common. Many of these differences in usage can be attributed to the time depth spent  with the symbol sets.

Astrobiology is defined as the study of the origin, evolution,
distribution, and future of life in the universe (NASA’s definition;
Des Marais et al. 2008). Astrobiology seeks to answer
fundamental questions about the beginning and evolution of
life on Earth, possible existence of extraterrestrial life, and
the future of life on Earth and beyond. Astrobiology scope is
delineated in the NASA’s astrobiology roadmap (Des Marais
et al. 2008). Specific goals include understanding the emergence
of life on Earth, determining how the early life on
Earth interacted and evolved with its changing environment,
understanding the evolutionary mechanisms and environmental
limits of life, exploring habitable environments in our solar
system and searching for life, understanding the nature and
distribution of habitable environments in the universe, and
recognizing signatures of life on the early Earth and on other
worlds. The NASA’s astrobiology map is being updated as
the astrobiology field advances. A similar roadmap has been
developed for astrobiology research in Europe (Horneck et al.
2015, 2016). The topic of these roadmaps is further discussed
and updated in Section 1 of this handbook.
Astrobiology is a young science that acquired its name
only in 1995 (named by Wes Huntress from NASA; Catling
2013). Astrobiology evolved from its predecessor, exobiology,
which is the study of the origin of life and of possible
life outside Earth (Dick and Strick 2004; Dick 2007). The
term exobiology was coined in 1960 (by Joshua Lederberg).

The difference between the two fields is that astrobiology is
broader and notably includes the evolution of life on Earth.
The exobiology era coincided with the space missions, notably
the Viking mission on Mars in 1976, which followed a
series of reconnaissance missions in the 1960s and early
1970s.
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Table.of.Contents

Preface......Page.12
Editor......Page.14
Contributors......Page.16

SECTION.I:.Astrobiology:.Definition,.Scope,.and.Education......Page.22
Chapter.1.1.Astrobiology:.Definition,.Scope,.and.a.Brief.Overview......Page.24
Chapter.1.2.Astrobiology.Goals:.NASA.Strategy.and.European.Roadmap......Page.36
Chapter.1.3.Online,.Classroom.and.Wilderness.Teaching.Environments:.Reaching.Astrobiology.Learners.of.All.Ages.Around.the.World......Page.48
Chapter.1.4.Astrobiology.as.a.Medium.of.Science.Education......Page.66
Chapter.1.5.Astrobiology-as-Origins-Story:.Education.and.Inspiration.across.Cultures......Page.70

SECTION.II:.Definition.and.Nature.Of.Life......Page.76
Chapter.2.1.Defining.Life:.Multiple.Perspectives......Page.78
Chapter.2.2.A.Generalized.and.Universalized.Definition.of.Life.Applicable.to.Extraterrestrial.Environments......Page.86
Chapter.2.3.Synthetic.Cells.and.Minimal.Life......Page.96
Chapter.2.4.Communication.as.the.Main.Characteristic.of.Life......Page.112

SECTION.III:.Origin.of.Life:.History,.Philosophical.Aspects,.and.Major.Developments......Page.128
Chapter.3.1.Philosophical.Aspects.of.the.Origin-of-Life.Problem:.Neither.by.Chance.Nor.by.Design.....Page.130
Chapter.3.2.Charles.Darwin.and.the.Plurality.of.Worlds:.Are.We.Alone?......Page.146
Chapter.3.3.An.Early.History.from.Buffon.to.Oparin......Page.158

SECTION.IV:.Chemical.Origins.of.Life:.Chemicals.in.the.Universe.and.Their.Delivery.on.the.Early.Earth;.Geology.and.Atmosphere.on.the.Early.Earth......Page.166
Chapter.4.1.Interstellar.Molecules.and.Their.Prebiotic.Potential......Page.168
Chapter.4.2.Formation.and.Delivery.of.Complex.Organic.Molecules.to.the.Solar.System.and.Early.Earth.....Page.186
Chapter.4.3.Organic.Molecules.in.Meteorites.and.Their.Astrobiological.Significance.....Page.198
Chapter.4.4.Ancient.Life.and.Plate.Tectonics......Page.216
Chapter.4.5.Atmosphere.on.Early.Earth.and.Its.Evolution.as.It.Impacted.Life......Page.228

SECTION.V:.Chemical.Origin.of.Life:.Prebiotic.Chemistry......Page.238
Chapter.5.1.Prebiotic.Chemistry.That.Led.to.Life.....Page.240
Chapter.5.2.Prebiotic.Chemical.Pathways.to.RNA.and.the.Importance.of.Its.Compartmentation......Page.256
Chapter.5.3.The.Hydrothermal.Impact.Crater.Lakes:.The.Crucibles.of.Life’s.Origin......Page.286
Chapter.5.4.Prebiotic.Chemistry.in.Hydrothermal.Vent.Systems......Page.318
Chapter.5.5.Prebiotic.Reactions.in.Water,.“On.Water,”.in.Superheated.Water,.Solventless,.and.in.the.Solid.State......Page.352
Chapter.5.6.The.Origin.and.Amplification.of.Chirality.Leading.to.Biological.Homochirality......Page.362
Chapter.5.7.Phosphorus.in.Prebiotic.Chemistry—An.Update.and.a.Note.on.Plausibility......Page.376
Chapter.5.8.Phosphorylation.on.the.Early.Earth:.The.Role.of.Phosphorus.in.Biochemistry.and.Its.Bioavailability......Page.382
Chapter.5.9.Silicon.and.Life......Page.392

SECTION.VI:.RNA.and.RNA.World:.Complexity.of.Life’s.Origins......Page.398
Chapter.6.1.Transitions:.RNA.and.Ribozymes.in.the.Development.of.Life......Page.400
Chapter.6.2.Three.Ways.to.Make.an.RNA.Sequence:.Steps.from.Chemistry.to.the.RNA.World......Page.416
Chapter.6.3.Coevolution.of.RNA.and.Peptides......Page.430
Chapter.6.4.Role.of.Cations.in.RNA.Folding.and.Function.....Page.442
Chapter.6.5.The.Origin.of.Life.as.an.Evolutionary.Process:.Representative.Case.Studies......Page.458
Chapter.6.6.The.Complexity.of.Life’s.Origins:.A.Physicochemical.View.....Page.484

SECTION.VII:.Origin.of.Life:.Early.Compartmentalization—Coacervates.and.Protocells......Page.502
Chapter.7.1.Oparin’s.Coacervates......Page.504
Chapter.7.2.Protocell.Emergence.and.Evolution......Page.512

SECTION.VIII:.Origin.of.Life.and.Its.Diversification..Universal.Tree.of.Life..Early.Primitive.Life.on.Earth..Fossils.of.Ancient.Microorganisms..Biomarkers.and.Detection.of.Life......Page.540
Chapter.8.1.The.Progenote,.Last.Universal.Common.Ancestor,.and.the.Root.of.the.Cellular.Tree.of.Life......Page.542
Chapter.8.2.Horizontal.Gene.Transfer.in.Microbial.Evolution.....Page.548
Chapter.8.3.Viruses.in.the.Origin.of.Life.and.Its.Subsequent.Diversification.....Page.556
Chapter.8.4.Carl.R..Woese.and.the.Journey.toward.a.Universal.Tree.of.Life.....Page.576
Chapter.8.5.Fossils.of.Ancient.Microorganisms...Page.588
Chapter.8.6.Biomarkers.and.Their.Raman.Spectral.Signatures:.An.Analytical.Challenge.in.Astrobiology...Page.618
Chapter.8.7.Fossilization.of.Bacteria.and.Implications.for.the.Search.for.Early.Life.on.Earth.and.Astrobiology.Missions.to.Mars......Page.630

SECTION.IX:.Life.under.Extreme.Conditions—Microbes.in.Space......Page.654
Chapter.9.1.Extremophiles.and.Their.Natural.Niches.on.Earth......Page.656
Chapter.9.2.Microbes.in.Space......Page.682
Chapter.9.3.Virus.Evolution.and.Ecology:.Role.of.Viruses.in.Adaptation.of.Life.to.Extreme.Environments......Page.698

SECTION.X:.Habitability:.Characteristics.of.Habitable.Planets.....Page.704
Chapter.10.1.The.Evolution.of.Habitability:.Characteristics.of.Habitable.Planets......Page.706

SECTION.XI:.Intelligent.Life.in.Space:.History,.Philosophy,.and.SETI.(Search.for.Extraterrestrial.Intelligence)......Page.720
Chapter.11.1.Mind.in.Universe:.On.the.Origin,.Evolution,.and.Distribution.of.Intelligent.Life.in.Space.....Page.722
Chapter.11.2.Where.Are.They?.Implications.of.the.Drake.Equation.and.the.Fermi.Paradox......Page.738
Chapter.11.3.SETI:.Its.Goals.and.Accomplishments......Page.748
Chapter.11.4.Humanistic.Implications.of.Discovering.Life.Beyond.Earth......Page.762

SECTION.XII:.Exoplanets,.Exploration.of.Solar.System,.the.Search.for.Extraterrestrial.Life.in.Our.Solar.System,.and.Planetary.Protection......Page.778
Chapter.12.1.Exoplanets:.Methods.for.Their.Detection.and.Their.Habitability.Potential......Page.780
Chapter.12.2.Solar.System.Exploration:.Small.Bodies.and.Their.Chemical.and.Physical.Conditions......Page.796
Chapter.12.3.Solar.System.Exploration:.Icy.Moons.and.Their.Habitability......Page.808
Chapter.12.4.Searching.for.Extraterrestrial.Life.in.Our.Solar.System......Page.822
Chapter.12.5.Planetary.Protection.....Page.840
Index......Page.856

This article presents possible determinants of an extraterrestrial intelligence (ETI) intentions towards the Earth. These determinants have then been organized in a model of pathways, that proposes in output the most likely ETI intention: destruction, domination, subordination, cohabitation, collaboration, or silent observation. The model of pathways aims mainly to illustrate the possible influence of these determinants and to contribute to the discussions about ETI contact risks assessment.

This paper outlines hypotheses relevant to the evolution of intelligent life and encephalization in the Phanerozoic. If general principles are inferable from patterns of Earth life, implications could be drawn for astrobiology. Many of the outlined hypotheses, relevant data, and associated evolutionary and ecological theory are not frequently cited in astrobiological journals. Thus opportunity exists to evaluate reviewed hypotheses with an astrobiological perspective. A quantitative method is presented for testing one of the reviewed hypotheses (hypothesis i; the diffusion hypothesis). Questions are presented throughout, which illustrate that the question of intelligent life's likelihood can be expressed as multiple, broadly ranging, more tractable questions.

In this article, anoxic and oxic hydrolyses of rocks containing Fe (II) Mg-silicates and Fe (II)-monosulfides are analyzed at 25 °C and 250-350 °C. A table of the products is drawn. It is shown that magnetite and hydrogen can be produced during low-temperature (25 °C) anoxic hydrolysis/oxidation of ferrous silicates and during high-temperature (250 °C) anoxic hydrolysis/oxidation of ferrous monosulfides. The high-T (350 °C) anoxic hydrolysis of ferrous silicates leads mainly to ferric oxides/hydroxides such as the hydroxide ferric trihydroxide, the oxide hydroxide goethite/lepidocrocite and the oxide hematite, and to Fe(III)-phyllosilicates. Magnetite is not a primary product. While the low-T (25 °C) anoxic hydrolysis of ferrous monosulfides leads to pyrite. Thermodynamic functions are calculated for elementary reactions of hydrolysis and carbonation of olivine and pyroxene and E-pH diagrams are analyzed. It is shown that the hydrolysis of the iron endmember is endothermic and can proceed within the exothermic hydrolysis of the magnesium endmember and also within the exothermic reactions of carbonations. The distinction between three products of the iron hydrolysis, magnetite, goethite and hematite is determined with E-pH diagrams. The hydrolysis/oxidation of the sulfides mackinawite/troilite/pyrrhotite is highly endothermic but can proceed within the heat produced by the exothermic hydrolyses and carbonations of ferromagnesian silicates and also by other sources such as magma, hydrothermal sources, impacts. These theoretical results are confirmed by the products observed in several related laboratory experiments. The case of radiolyzed water is studied. It is shown that magnetite and ferric oxides/hydroxides such as ferric trihydroxide, goethite/lepidocrocite and hematite are formed in oxic hydrolysis of ferromagnesian silicates at 25 °C and 350 °C. Oxic oxidation of ferrous monosulfides at 25 °C leads mainly to pyrite and ferric oxides/hydroxides such as ferric trihydroxide, goethite/lepidocrocite and hematite and also to sulfates, and at 250 °C mainly to magnetite instead of pyrite, associated to the same ferric oxides/hydroxides and sulfates. Some examples of geological terrains, such as Mawrth Vallis on Mars, the Tagish Lake meteorite and hydrothermal venting fields, where hydrolysis/oxidation of ferromagnesian silicates and iron(II)-monosulfides may occur, are discussed. Considering the evolution of rocks during their interaction with water, in the absence of oxygen and in radiolyzed water, with hydrothermal release of H2 and the plausible associated formation of components of life, geobiotropic signatures are proposed. They are mainly Fe(III)-phyllosilicates, magnetite, ferric trihydroxide, goethite/lepidocrocite, hematite, but not pyrite.

If there is any way that humankind is unique in the galaxy, perhaps it is insofar as on Earth, our joys and our pains are so exquisitely balanced. If pain is an obstacle that has been overcome by more advanced extraterrestrial civilizations long ago, then our descriptions of our suffering may significantly contribute to other civilizations’ understanding of our species and our culture. By drawing on some of the same methods Freudenthal uses in Lincos to describe the physical universe, we can also provide detailed descriptions of our bodies. Portraying ourselves as embodied and vulnerable, we might provide outward signs of our inward distress. In addition, the link between the physical and the subjective experiences of pain provides a vehicle to address one of the greatest challenges of interstellar communication: explaining human subjectivity.

Previous discussions of interstellar messages that could be sent to extraterrestrial intelligence have focused on descriptions of mathematics, science, and aspects of human culture and civilization. Although some of these depictions of humanity have implicitly referred to our aspirations, this has not clearly been separated from descriptions of our actions and attitudes as they are. In this paper, a methodology is developed for constructing interstellar messages that convey information about our aspirations by developing a taxonomy of maxims that provide guidance for living. Sixty-six maxims providing guidance for living were judged for degree of similarity to each of other. Quantitative measures of the degree of similarity between all pairs of maxims were derived by aggregating similarity judgments across individual participants. These composite similarity ratings were subjected to a cluster analysis, which yielded a taxonomy that highlights perceived interrelationships between individual maxims and that identifies major classes of maxims. Such maxims can be encoded in interstellar messages through three-dimensional animation sequences conveying narratives that highlight interactions between individuals. In addition, verbal descriptions of these interactions in Basic English can be combined with these pictorial sequences to increase intelligibility. Online projects to collect messages such as the SETI Institute's Earth Speaks and La Tierra Habla, can be used to solicit maxims from participants around the world.

As scholars involved with the Search for Extraterrestrial Intelligence (SETI) have contemplated how we might portray humankind in any messages sent to civilizations beyond Earth, one of the challenges they face is adequately representing the diversity of human cultures. For example, in a 2003 workshop in Paris sponsored by the SETI Institute, the International Academy of Astronautics (IAA) SETI Permanent Study Group, the International Society for the Arts, Sciences and Technology (ISAST), and the John Templeton Foundation, a varied group of artists, scientists, and scholars from the humanities considered how to encode notions of altruism in interstellar messages http://publish.seti.org/art_science/2003. Though the group represented 10 countries, most were from Europe and North America, leading to the group's recommendation that subsequent discussions on the topic should include more globally representative perspectives. As a result, the IAA Study Group on Interstellar Message Construction and the SETI Institute sponsored a follow-up workshop in Santa Fe, New Mexico, USA in February 2005. The Santa Fe workshop brought together scholars from a range of disciplines including anthropology, archaeology, chemistry, communication science, philosophy, and psychology. Participants included scholars familiar with interstellar message design as well as specialists in cross-cultural research who had participated in the Symposium on Altruism in Cross-cultural Perspective, held just prior to the workshop during the annual conference of the Society for Cross-cultural Research www.seti.org/altruism. The workshop included discussion of how cultural understandings of altruism can complement and critique the more biologically based models of altruism proposed for interstellar messages at the 2003 Paris workshop. This paper, written by the chair of both the Paris and Santa Fe workshops, will explore the challenges of communicating concepts of altruism that draw on both biological and cultural models.

Pictorial messages have previously been advocated for interstellar communication because such messages are presumed to be capable of presenting information in a non-arbitrary and easily intelligible manner. In contrast to this view, pictorial messages actually represent information in a partially conventional way. This point is demonstrated by examining pictorial representations of human beings from a range of cultures. While such representations may be understood quite readily by individuals familiar with the conventions of a particular culture, to the uninitiated outsider, such representations can be unintelligible. In spite of the partially arbitrary nature of pictorial representation, we may be able to construct messages that would teach extraterrestrial intelligence (ETI) some of the conventions by which we view pictures. One such approach is to pair numerical information about geometrical objects with pictorial representations of the same objects. Problems of conventionality can also be addressed in part through use of (1) multiple representations of the same object, (2) contextual cues, (3) three- and four-dimensional representations and (4) non-visual representations.

I would like to give my thanks to Inge Loes ten Kate for writing this excellent analysis named “Organic molecules on Mars” and I would also like to thank Science for publishing it. The author is correct when he says that the recent findings of Curiosity rover are “breakthroughs in astrobiology”. But I have some disagreements when he states the following concerning NASA’s 1976 Viking mission: “However, neither signs of life nor organic compounds were detected in the regolith samples analyzed during this mission”.

A fundamental question in the field of social studies of science is how research fields emerge, grow and decline over time and space. This study confronts this question here by developing an inductive analysis of emerging research fields represented by human microbiome, evolutionary robotics and astrobiology. In particular, number of papers from starting years to 2017 of each emerging research field is analyzed considering the subject areas (i.e., disciplines) of authors. Findings suggest some empirical laws of the evolution of research fields: the first law states that the evolution of a specific research field is driven by few scientific disciplines (3-5) that generate more than 80% of documents (concentration of the scientific production); the second law states that the evolution of research fields is path-dependent of a critical discipline (it can be a native discipline that has originated the research field or a new discipline emerged during the social dynamics of science); the third law states that a research field can be driven during its evolution by a new discipline originated by a process of specialization within science. The findings here can explain and generalize, whenever possible some properties of the evolution of scientific fields that are due to interaction between disciplines, convergence between basic and applied research fields and interdisciplinary in scientific research. Overall, then, this study begins the process of clarifying and generalizing, as far as possible, the properties of the social construction and evolution of science to lay a foundation for the development of sophisticated theories.

Recently, an exoplanetary system containing seven Earth-sized terrestrial planets, three of which orbit the central
M-dwarf star in its habitable zone, was discovered. Such systems may be common, as this type of star makes up
almost 80% of all stars. Based on a critical literature review, this paper defines the criteria for exoplanet habitability

and adopts the habitable zone criterion as the most basic one for use in absence of data and the novel Statistical-
likelihood Exo-Planetary Habitability Index as the presently most suited for assessing M-dwarf exoplanets. It further

describes the feasible methods employed for the detection of this type of exoplanets (the transit and radial velocity

method), provides an account of the environmental condition constraints imposed by their close orbit around an M-
dwarf star, and evaluates these conditions against those deemed suitable for the development and survival of life.

The details of the known and suspected population of exoplanets in the habitable zone of M-dwarf stars are then
compared to the adopted habitability criteria, and it is concluded that the frequency with which any such planets
can indeed be said to be habitable cannot currently be estimated due to the small sample size. The prospects of
further characterising this subset of exoplanets in the future, identifying them as habitable and possibly detecting
any bio-signatures are subsequently discussed. In order to accelerate the quest for habitable and inhabited
exoplanets, aggressive, focused searches and targeted studies directed at planets in the habitable zone of M-dwarf
stars are proposed.