Microbial mats are an extant paradigm of the earliest ecosystems. Defining the minimal ecosystem requirements necessary for the survival and proliferation of organisms is crucial in the search for extraterrestrial life and for establishing Earth-like ecosystems beyond our planet. Microbial mats are multilayered biofilms that operate as almost closed systems with persistent oxidation-reduction gradients and restricted vertical flows. Under the driving force of light the components interact and feedback flows become established. The community is the highest biological unit in an ecological hierarchy. The knowledge of the community composition is essential to understand the microbial mats dynamics. Understanding the factors that determine ecosystem stability has been one of the main challenges for ecologists. It has been pointed that both major and minor populations are important for maintaining ecosystem stability. Spirochetes represent one of the minor heterotrophic groups (ca. 1% total population) in microbial mats. However, when samples were examined with primers specific for the spirochete group, highly diverse collections of spirochete 16S rDNA were uncovered. Spirochetes may constitute a ubiquitous component of microbial mats that are linked to other microbial communities by robust trophic interactions.

Clonal isolates of cyanophytes were collected from several study sites in the Dugway Proving Ground and San Rafael Sell Overlook in Utah. We identified 32 taxa belonging to 24 cyanobacterial genera. Some taxa were widely distributed, occurring in all sites. For example, the members of the filamentous cyanobacterial genera Leptolyngbya, Microcoleus, Nostoc and Trichocoleus and members of the coccoid genus Aphanocapsa were common to all sites. On the other hand, members of the cyanobacterial genus Calothrix were rarely encountered at the Dugway site but were recovered frequently from the San Rafael site. We were able to compare disturbed and undisturbed sites located close together in the San Rafael Overlook. We found that the genera Spirirestis and Cyanosarcina, were found exclusively in the undisturbed site. A number of the taxa recovered could be identified only to the genus level because they did not match previously published species descriptions. Since we have recovered both prokaryotic eukaryotic taxa new to science in our previous work, it is quite likely that some of these isolates do indeed represent new cyanobacterial species. This study is the most extensive characterization of cyanobacteria from soil crusts in a semi-arid North American deserts. It expands our knowledge of the diversity of the cyanobacterial components of North American soil crusts.

Cyanobacteria (cyanophyta, cyanoprokaryota, and blue-green algae) are an ancient, diverse and abundant group of photosynthetic oxygenic microorganisms. Together with other bacteria and archaea, the cyanobacteria have been the dominant life forms on Earth for over 3.5 billion years. Cyanobacteria occur in some of our planets most extreme environments - hot springs and geysers, hypersaline and alkaline lakes, hot and cold deserts, and the polar ice caps. They occur in a wide variety of morphologies. Unlike archaea and other bacteria, which are typically classified in pure culture by their physiological, biochemical and phylogenetic properties, the cyanobacteria have historically been classified based upon their size and morphological characteristics. These include the presence or absence of heterocysts, sheath, uniseriate or multiseriate trichomes, true or false branching, arrangement of thylakoids, reproduction by akinetes, binary fission, hormogonia, fragmentation, presence/absence of motility etc. Their antiquity, distribution, structural and chemical differentiation, diversity, morphological complexity and large size compared to most other bacteria, makes the cyanobacteria ideal candidates for morphological biomarkers in returned Astromaterials. We have obtained optical (nomarski and phase contrast)/fluorescent (blue and green excitation) microscopy images using an Olympus BX60 compound microscope and Field Emission Scanning Electron Microscopy images and EDAX elemental compositions of living and fossil cyanobacteria. The S-4000 Hitachi Field Emission Scanning Electron Microscope (FESEM) has been used to investigate microfossils in freshly fractured interior surfaces of terrestrial rocks and the cells, hormogonia, sheaths and trichomes of recent filamentous cyanobacteria. We present Fluorescent and FESEM Secondary and Backscattered Electron images and associated EDAX elemental analyses of recent and fossil cyanobacteria, concentrating on representatives of the genera Calothrix, Leptolyngbya, Lyngbya, Planktolyngbya and Oscillatoria.

The study of alkaliphilic microbial communities from anaerobic sediments of Owens and Mono Lakes in California has established the presence of active microbial cellulolytic processes in both studied lakes. The prior study of the microbial diversity of anaerobes in Mono Lake showed that the trophic chain of organic decomposition includes secondary anaerobes that previously were found to be unknown species (Spirochaeta americana, Tindallia californiensis, and Desulfonatronum thiodismutans). As we published earlier, the secondary anaerobes of Owens Lake morphologically were found to be very similar to those of Mono Lake. However, detailed comparison of the physiology and genetics has led to the conclusion that some links of organic decomposition in the trophic chain of the Owens Lake community are represented by a different unknown species. A new isolate of a sugarlytics free-living spirochete from Owens Lake ASpC2, which morphologically was similar to S. americana AspG1T isolated from Mono Lake, was found to have a different metabolic capacity such as the lack of capability to produce hydrogen during the fermentation of sugars. Furthermore, from the same microbial community of Owens Lake, another sugarlytics spore-forming alkaliphilic strain SCA was isolated in pure culture and described. Here we discuss the universal structure of the microbial community, types of microbial communities, review some hypothesis about Earth's Primordial Ocean and relevant new discoveries about water on Mars. This paper also presents some of the characteristics of novel isolates from anaerobic sediments of Owens Lake as a unique relic ecosystem of Astrobiological significance, and describes the participation of these strains in the process of cellulose degradation.

Newly found biomorphic microstructures from the Upper Archaean (lopian) rocks from Northern Karelia are described. The presence of various microorganisms of a bacterial nature and even cyanobacteria (and possibly eukaryotic forms) is suggested. The necessity of employing methods of electron microscopy, as well as traditional methods, while studying the very early manifestations of life in Archaean and Early Proterozoic is noted.

In the light of the significance of extremophiles as model organisms to access possible extraterrestiral life, we provide a short review of the systematics of thermophilic Archaea, and introduce our exploratory research of novel thermophilic Archaea from hot springs in Japan. Up to date, we have isolated 162 strains of the thermophilic Archaea from hot springs in Japan by the enrichment method or the most probable number/PCR method, and the 16S rRNA gene sequences were determined to reveal their phylogenetic diversity. The sequence comparison illustrated that the isolates belonged to the orders Sulfolobales (117 isolates) , Thermoproteales (29 isolates), Desulfurococcales (8 isolates) and Thermoplasmatales (8 isolates), and there were six separate lineages representing new genera, and at least seven new species as predicted by the phylogenetic distance to known species. The collection of isolates not only included novel taxa but would give some implication for a necessity to reevaluate the current taxonomy of the thermophilic Archaea.

Dissimilatory Fe(III) reduction (i.e., iron respiration) among hyperthermophilic microorganisms may be an ancient and widespread form of metabolism on earth and is a good candidate metabolism for putative life elsewhere. Iron respiration coupled with H₂ oxidation at 100°C is highly favorable thermodynamically and can occur independent of photosynthesis. Hyperthermophilic iron reducers have been isolated from terrestrial hot springs, deep-sea hydrothermal vents, and deep (> 1,000 m) subsurface samples such as petroleum reservoirs, geothermal pools and mining operations. The hyperthermophilic archaeon Pyrobaculum aerophilum can reduce both soluble (Fe(III) citrate) and insoluble (poorly crystalline Fe(III) oxide) forms of iron. Direct contact is not necessary for reduction of insoluble iron suggesting the organism uses either an extracellular electron shuttle or a chelator for iron reduction. Growth on iron by a newly isolated Pyrobaculum sp. was measured at pH 5 where growth on O₂, NO₃- and S° no longer occurred, which broadened the pH range for growth of the organism. Environmental biomarkers of iron reducers may include extracellular iron chelators and electron shuttles, lipids, and 16S rRNAs. Markers of iron respiration may include magnetite formation and stable iron isotope fractionation. The identification of biomarkers for iron respiration at high temperatures is in its infancy but could provide insight into the microbial ecology of the subsurface biosphere, past and present, and provide targets for missions to other planets and moons.

Extremophilic organisms dwell in environments that are characterized by high or low temperatures (thermophiles or psychrophiles), very low or high pH-values (acidophiles or alkalophiles), high salt concentrations (halophiles), high pressure (barophiles), or extreme drought (xerophiles). Many extremophiles are microbes, and many also belong to the prokaryota. Galdieria sulphuraria, however, is a member of a group of extremophilic eukaryotes that are named Cyanidiales. Cyanidiales are unicellular red micro-algae that occur worldwide in hot acidic waters, volcanic calderas, and in human-made acidic environments such as acidic mine drainage. G. sulphuraria has a unique position within the Cyanidiales because, in contrast to the other obligate photoautotrophic members of this group, it is able to grow photoautotrophically, mixotrophically, and heterotrophically. It is not only resistant to acid (pH 0) and heat (56^oC), but also to high salt (1.5 M NaCl), toxic metals, and many other abiotic stressors. This unusual combination of features such as thermophily, acidophily, resistance to a wide array of abiotic stressors, and an extraordinary metabolic plasticity make G. sulphuraria highly interesting model organism to study adaptation to extreme environments. We have started a genomics approach to gain insight into the biology of G. sulphuraria and to identify genes and gene products critical for survival under extreme conditions. To this end, we pursue a whole-genome, shotgun sequencing approach towards unraveling the genome sequence of G. sulphuraria. We report here on the status quo of the genome-sequencing project and we summarize what we have learned to date from the genome sequence about the biology of this truly unique extremophile.

Searching for life in astromaterials to be delivered from the future missions to extraterrestrial bodies is undoubtedly related to studies of the properties and signatures of living microbial cells and microfossils on Earth. The Antarctic glacier and Earth permafrost habitats, where living microbial cells preserved viability for millennia years due to entering the anabiotic state, are often regarded as terrestrial analogs of Martian polar subsurface layers. For the future findings of viable microorganisms in samples from extraterrestrial objects, it is important to use a combined methodology that includes classical microbiological methods, plating onto nutrient media, direct epifluorescence and electron microscopy examinations, detection of the elemental composition of cells, PCR and FISH methods. Of great importance is to ensure authenticity of microorganisms (if any in studied samples) and to standardize the protocols used to minimize a risk of external contamination. Although the convincing evidence of extraterrestrial microbial life will may come from the discovery of living cells in astromaterials, biomorphs and microfossils must also be regarded as a target in search of life evidence bearing in mind a scenario that living microorganisms had not been preserved and underwent mineralization. Regarding the vital importance of distinguishing between biogenic and abiogenic signatures and between living and fossil microorganisms in analyzed samples, it is worthwhile to use previously developed approaches based on electron microscopy examinations and analysis of elemental composition of biomorphs in situ.

In this paper we describe "extremophiles" and "survivophiles" and consider their role in the continuity and perpetuity of life throughout Earth's turbulent history. The term "extremophiles" refers to organisms active in what are considered by human beings to be extreme physical or chemical environments. The term "survivophiles" collectively refers to organisms capable of assuming reversible inactive states (suspended or latent), which enable them to survive harsh conditions until what they consider hospitable conditions to metabolic activity return. We present the various biological states of individual organisms (active, inactive, transition) and how these states relate to the dynamic biological-physicalchemical context that makes up an organism's environment. We argue that within these states the special adaptations of extremophiles and survivophiles have allowed life as a phenomenon to withstand global catastrophes, which include massive volcanic eruptions, supernovae explosions, and asteroid impacts. These are the catastrophes that changed the environments on Earth too quickly for organisms to adapt by Darwinian evolution. We suggest that genetic adaptations of extremophiles both allow them to thrive under at least some of the harsh conditions caused by catastrophes and these same adaptations also make them a source of genetic information for intrinsically stable macromolecules. This genetic information for stable macromolecules can be shared with other organisms through lateral gene transfer. Similarly, the adaptations of survivophiles increase survival during catastrophes and provide a source of genes for bio-stabilizing molecules (e.g., heat shock proteins, trehalose and other organic solutes). We conclude that the strategies and the specialized genes for growth and survival of extremophiles and survivophiles impact the continuity and perpetuity of life during global catastrophes by expanding the range of possible refugia during these events and by providing genetic information to other organisms.

Organisms on Earth commonly exhibit a circadian rhythm, which is synchronized to the 24-hour day-night (diurnal) cycle of the planet. However, if isolated from strong environmental time cues (e.g., light-dark, temperature, etc.), many organisms revert to a "free-running" rhythm that is close to, but significantly different from, the diurnal cycle. Such a free-running rhythm is a distinct biological feature, as it requires an endogenous pacemaker that is not just passively driven by rhythms in the environment. On Mars, a free-running rhythm (i.e., significantly different from the Martian diurnal cycle of 24.66 hours) would constitute independent proof of the presence of living organisms. Evidence for such a circadian biosignature from Mars has been sought in the data sent by the 1976 Viking Labeled Release (LR) life detection experiment . In the search for circadian rhythmicity, oscillatory fluctuations in the amount of radiolabeled gas in the headspace of the LR test cell of Viking Lander 2, test cycle 3, were studied. The cycle duration of the LR oscillations examined did not differ significantly from that of the daily cell temperature oscillations controlled ultimately by the Martian diurnal cycle. Thus, these specific LR oscillations produced no independent evidence for an endogenous biological origin. However, it was found that the amplitudes of the oscillations in the gas (presumably CO₂) were greater than could be accounted for by the most likely non-biological mechanism (i.e., temperature-induced changes in soil solubility of CO₂). The possibility thus remained that biological activity, synchronized to the Martian diurnal cycle, could be responsible for at least part of the oscillatory activity in the LR signals. We now propose to consider all data from the nine active and control cycles of the Martian LR experiment. A comprehensive set of null and alternative hypotheses is proposed for statistical testing using the digitized data. Advanced, statistically rigorous methods of circadian rhythm analysis are laid out to determine whether an endogenous circadian rhythm was present. The data will be analyzed for any free-running rhythm deviating from the Martian diurnal cycle. The possibility that nutrient administration altered the phase (i.e., timing) of the LR oscillations (as has been observed in terrestrial microorganisms) will also be examined. Any indication that the signal may be of biological origin will be tested against the hypothesis that it was caused solely by temperature-induced changes (e.g., temperature-dependent changes in soil physical chemistry). The focus of this paper is to develop broadly accepted methodology to determine definitively whether the LR data exhibit circadian characteristics that imply the involvement of Martian biology.

The possible existence of life on Mars is now gaining credence. Evidence consistent with or supporting the presence of extant microbial life, as reported by a life detection experiment on the Viking Mission in 1976, has been rapidly accumulating from spacecraft orbital and lander operations, and from terrestrial observations. Vast oceans of frozen water near the planet's surface are being discovered, with strong indications of recent or present liquid flows, and theory and laboratory experiment have demonstrated that liquid water should exist on the surface of Mars. The biosphere on Earth has been extended into extreme environments until recently thought inimical to life. Places void of life have become rare. No life requirement has been found lacking on Mars. It is possible that, by the time of this 50th Anniversary SPIE Meeting, the paradigm shift accepting life beyond the Earth may have been made. Mankind will then emerge from its ancient fear of loneliness into a new fear of anticipation of what that still unidentified life might portend. The author attempts to apply Darwinian principles of evolution to life on Mars under the selection pressures, opportunities and constraints that have been imposed by past and present Martian conditions. Starting with the type of cell believed to have begun the evolutionary process on Earth, he speculates on what the current life on Mars may be like in form and function, including what threat or promise it might hold for Earth life.

The electron-microscope analysis of the Orgeuil carbonaceous chondrite, thought to be the extinct core of a comet, shows many archaen microfossils adapted for both cold and hot liquid water environments. Since water is a prerequisite for life, its presence on a comet would have important implications for interplanetary cross-contamination of the planets as well as strongly impact the dynamics and evolution of a comet. Therefore we develop a wet comet model to explore the consequences of liquid water on Mars-crossing comets and hypothesize that all the periodic comets, such as P/Halley, P/Wild-2, and P/Borrelly show signs of significant liquid water processing. The wet comet model is shown to be compatible with observation, as well as provide significantly better explanations for well-known cometary anomalies. Finally, the model predicts that the results of both Rosetta and Deep Impact missions will deviate from expectations.

Astrobiology is a rapidly evolving discipline and, in order for its information to be passed on, it is urgent and necessary for Astrobiology to be integrated into the curricular domain, as well as into public and private scientific policies. The latter would contribute to the understanding of both the dynamic construction of scientific knowledge, and the spreading of science as a cultural imperative. This paper continues our previous work on Astrobiology education and public outreach. In this sense, we will present a curricular proposal on Astrobiology, which we would like to see integrated into the scientific areas of Portuguese secondary schools. To achieve this goal, it was necessary to select the most adequate and important key ideas for teaching, and to adapt the most complex scientific language to the school context. Finally, the right tools and strategies were created and developed to attain the proposed objectives. Several examples of these ideas, tools and strategies are discussed in the present article.

We are currently developing a teaching module on the NASA's Planetary Protection Program for UW-Parkside SENCER courses. SENCER stands for Science Education for New Civic Engagements and Responsibility. It is a national initiative of the National Science Foundation (NSF), now in its fifth year, to improve science education by teaching basic sciences through the complex public issues of the 21^st century. The Planetary Protection Program is one such complex public issue. Teaching astrobiology and the NASA's goals via the Planetary Protection module within the SENCER courses seems to be a good formula to reach large number of students in an interesting and innovative way. We shall describe the module that we are developing. It will be launched on our web site titled "Astrobiology at Parkside" (http://oldweb.uwp.edu/academic/chemistry/kolb/organic_chemistry/, or go to Google and then to Vera Kolb Home Page), and thus will be available for teaching to all interested parties.

The existence of life places strong constraints on the cosmological initial conditions and the laws of physics. Cosmologists have long been intrigued by the "unreasonable" bio-friendliness of the universe in this regard. The explanation of choice is now the so-called multiverse cosmological model, which emerges naturally by combining the inflationary universe scenario with string theory. However, in the absence of an efficient panspermia mechanism, the question of whether or not life is widespread in the universe is not addressed by cosmology. Rather, it hinges on whether biogenesis is dominated by chance, or some elusive "life principle". One way to test the fashionable, but as-yet unjustified, claim that life arises readily on earth-like planets is to seek evidence for multiple genesis events on Earth. I offer some proposals for experimental test.

The quest for conclusive evidence of microfossils in meteorites has been elusive. Abiotic microstructures, mineral grains, and even coating artifacts may mimic unicellular bacteria, archaea and nanobacteria with simple spherical or rod morphologies (i.e., cocci, diplococci, bacilli, etc.). This is not the case for the larger and more complex microorganisms, colonies and microbial consortia and ecosystems. Microfossils of algae, cyanobacteria, and cyanobacterial and microbial mats have been recognized and described from many of the most ancient rocks on Earth. The filamentous cyanobacteria and sulphur-bacteria have very distinctive size ranges, complex and recognizable morphologies and visibly differentiated cellular microstructures. The taphonomic modes of fossilization and the life habits and processes of these microorganisms often result in distinctive chemical biosignatures associated with carbonization, silicification, calcification, phosphatization and metal-binding properties of their cell-walls, trichomes, sheaths and extracellular polymeric substances (EPS). Valid biogenicity is provided by the combination of a suite of known biogenic elements (that differ from the meteorite matrix) found in direct association with recognizable and distinct biological features and microstructures (e.g., uniseriate or multiseriate filaments, trichomes, sheaths and cells of proper size/size range); specialized cells (e.g., basal or apical cells, hormogonia, akinetes, and heterocysts); and evidence of growth characteristics (e.g., spiral filaments, robust or thin sheaths, laminated sheaths, true or false branching of trichomes, tapered or uniform filaments) and evidence of locomotion (e.g. emergent cells and trichomes, coiling hormogonia, and hollow or flattened and twisted sheaths). Since 1997 we have conducted Environmental and Field Emission Scanning Electron Microscopy (ESEM and FESEM) studies of freshly fractured interior surfaces of carbonaceous meteorites, terrestrial rocks, living, cryopreserved and fossilized extremophiles and cyanobacteria. These studies have resulted in the detection of mineralized remains of morphotypes of filamentous cyanobacteria, mats and consortia in many carbonaceous meteorites. These well-preserved and embedded microfossils are consistent with the size, morphology and ultra-microstructure of filamentous trichomic prokaryotes and degraded remains of microfibrils of cyanobacterial sheaths. EDAX elemental studies reveal that the forms in the meteorites often have highly carbonized sheaths in close association with permineralized filaments, trichomes, and microbial cells. The eextensive protocols and methodologies that have been developed to protect the samples from contamination and to distinguish recent contaminants from indigenous microfossils are described recent bio-contaminants. Ratios of critical bioelements (C:O, C:N, C:P, and C:S) reveal dramatic differences between microfossils in Earth rocks and meteorites and in the cells, filaments, trichomes, and hormogonia of recently living cyanobacteria. The results of comparative optical, ESEM and FESEM studies and EDAX elemental analyses of recent cyanobacteria (e.g. Calothrix, Oscillatoria, and Lyngbya) of similar size, morphology and microstructure to microfossils found embedded in the Murchison CM2 and the Orgueil CI1 carbonaceous meteorites are presented

Last year at this symposium we introduced a strategy for the automated detection of fossils during robotic missions to Mars using both structural and chemical signatures. The strategy employs a measure derived from information theory, lossless compression of photographic images, to estimate the relative complexity of a putative fossil compared to the rock matrix. Following target selection unsupervised multifactor cluster analysis of elemental abundance distributions provides an initial classification of the data. This autonomous classification is then confirmed using a non-linear stochastic neural network to produce a Bayesian estimate of classification accuracy. We have now employed this strategy to explore extant and fossil cyanobacteria from a variety of extreme terrestrial environments and microfossils and abiotic microstructures found in-situ in freshly fractured internal surfaces of carbonaceous meteorite. Elemental abundances (C, N, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, Fe) obtained for both extant and fossil cyanobacteria produce signatures distinguishing them from meteorite targets and from one another. Fossil cyanobacteria exhibit significant loss of C, N, O, P, and Ca and increases in Al, Si, S, and Fe relative to extant organisms. Orgueil structures exhibit decreased abundances for C, N, Na, P, Cl, K, and Ca; and increases in Mg, S, and Fe relative to extant cyanobacteria. Fossil cyanobacteria are distinguished from Orgueil samples by relative increases in Al, Si, and Fe; and by diminished O and Mg. Compression indices verify that variations in random and redundant textural patterns between perceived forms and the background matrix contribute significantly to morphological visual identification. The results provide a quantitative probabilistic methodology for discriminating putatitive fossils from the surrounding rock matrix and from extant organisms using both structural and chemical information. The techniques described appear applicable to the geobiological analysis of meteoritic samples or in situ exploration of the Mars regolith.

Here we re-examine the 1971 description of the acid-resistant, organic "hollow spheres" of the Orgueil meteorite by Rossignol-Strick and Barghoorn. They form a possible basis for comparison with the results of recent studies of the Orgueil meteorite that have been carried out at the NASA/Marshall Space Flight Center with the S-4000 Hitachi Field Emission Scanning Electron Microscope (FESEM). These investigations have revealed the presence of numerous carbon encrusted spherical magnetite platelets and spherical and ovoid bodies of elemental iron in-situ in freshly fractured interior surfaces of the meteorite. Their size range is from 5 to 12 microns. High-resolution images reveal that these bodies are also encrusted with a thin carbonaceous sheath and are surrounded by short nanofibrils shown as made of high purity iron by EDAX elemental analysis. We present high resolution FESEM images and associated EDAX elemental analyses of these forms and attempt to determine if they are representatives of the same population of indigenous microstructures as the hollow spheres.

The appearance of Bacteria, Eukaryotes, Metaphyta, Metazoa, etc., as well as the oxygenation of the atmosphere, took place much earlier than was formerly believed. The paleontological data clearly indicate that the difference in the surface temperature on the Earth from the Archaean to the present time was no more than 35-45° C.

As technology advances, we have more possibilities to search for past life, looking for biosignatures in the rock record. Even when these biosignatures can be chemical compounds, the irrevocable evidence of past life would be life itself preserved as fossils. Besides the pure shape, extra information such as the paleoenvironment, biotic associations, and the age of the rocks, can be retrieved from fossils to understand their significance and the context in which they developed. However, much of that information is rarely well preserved, giving fossils a wide range for speculation. Furthermore, abiotic structures can sometimes be easily mistaken as fossils, leading to wrong interpretations. Depending on the mode of fossilization and the type of organism, more or fewer characteristics would be available for interpretation, and depending on the techniques used for observation, those characteristics would be more or less appreciated. In permineralized organisms, internal and external structures can be observable with simple techniques (e.g. thin sections), revealing basic anatomic features that can yield trusty identifications. An example of remarkable organisms with these characteristics is found in the North-East region of Sonora, Mexico. Cretaceous sequences (70-72 Ma old) from the Tarahumara Formation contain several chert horizons where palm roots, freshwater aquatic plants, pollen grains, flowers, seeds, small crustaceans, algae, and cyanobacteria (among others) are commonly found, reflecting the extense diversity existing at that time. One of the Formation's localities, the Huepac Chert, exhibits several stromatolitic horizons in close relation with black chert that harbors a number of permineralized microfossils. About 65 different morphotypes have been described and some have been identified as cyanobacteria, chlorophyceans, and diatoms. These comparisions allowed us to conclude that some had benthonic habits, being perhaps stromatolite constructors. Others appear to be strict freshwater planktonic dwellers, which constrain even more the paleoenvironmental conditions and support geological studies leaning toward freshwater environments. Taking the Huepac microfossils as an example, it is strongly highlighted that morphology, size, and spatial arrangement are key for the identification of microfossils, and should be considered as essential resources of information when looking for life in the geological record on Earth and other planets.

Stromatolites represent a multifarious system of nested, physically, chemically, and biologically influenced components that range in scale from microscopic to macroscopic. These components can include microorganisms, organic compounds of microorganisms, sediment grains, precipitated sediment, sedimentary textures (fabrics), microstructure, laminae, domes, columns, branched columns, and cones. Millimeter to meter scale edifices (stromatolites) are the result. Stromatolites once played a significant role in establishing life's presence on the early Earth, but now a shift away from reliance on stromatolites is occurring. There is a perception that Archean stromatolite-like structures have low reliability to signal life. This is likely due to (1) no unified theory on stromatolite morphogenesis, (2) no valid or appropriate modern analog to use in the interpretation of Archean stromatolites, and (3) disagreement on how to define the word stromatolite. No single feature or line of evidence has yet been found that can unequivocally indicate a biogenic nature for a stromatolite. However, a range of features and their combinations that are well documented for the vast majority of fossil stromatolites and are found in some living stromatolites, are difficult, if not impossible, to account for by inorganic processes. Morphology remains a valid criterion to indicate biogenicity.

The origin of life on Earth continues to be one of the greatest mysteries of modern science. The fact that geochemical evidence for life may extend back to the earliest portion of the terrestrial rock record (approx. 4.0 Ga) makes it impossible to state with any certainty whether life originated on Earth or if it was introduced to Earth. Similarly, since a living system has never been synthesized in the laboratory, the requisite conditions and subsequent pathways for that origin remain unknown. It is this lack of definitive information that continues to inspire us to search outside the Earth for clues to life's origins. However, our ability to determine if life as we know it presently exists or existed elsewhere in our solar system or beyond depends on the establishment of criteria that can be used to determine its existence and to distinguish it from present-day life on Earth. The latter is critical, as it is extremely difficult to completely avoid contamination during sample collection and analysis. This is especially true with respect to materials returned to Earth, as is planned for future Mars' missions. Given their ubiquity and unique stable isotope compositions resulting from fractionations associated with their respective abiotic and biotic syntheses, amino acids are one of the classes of compounds best suited for establishing the existence of life as we know it. Criteria will be presented for detecting life and its possible precursors elsewhere in the solar system based on the stable isotope compositions of this important class of compounds.

The concept of symbiogenesis was introduced in 1909 by the Russian biologist Constantin Merezhkowsky as "the origin of organisms by the combination or by the association of two or several beings which enter into symbiosis". In this article we develop this idea, associated to the Freeman Dyson's hypothesis, applied to the early evolutive stages of life, considering that it could be a possible main rule in the appearance and development of life conditions on Earth and elsewhere. A cooperative, synergistic strategy should be considered as having been the determinant in the development of the survival of the fittest, especially under extremely adverse environmental conditions. This concept must be also applied to the first communities of cells as the base supporting evolution of the early "tree of life". Cells, like we have previously described, can be included in a new cellular concept entitled, "symbiocell", since survival of the community under such adverse conditions required a cooperative, synergistic strategy. Similar principles could also be used to understand chemical pre-biotic evolution. We believe that astrobiologists should consider it as a new approach to understand organic and biological evolution.

Recent findings by the NASA's Mars Exploration Rovers and ESA's Mars Express indicate that during an earlier era in the planets' evolution, evaporation of surface water may have left behind vast evaporite deposits^1,2,3. This makes the possibility of finding biological material preserved in halite inclusions most intriguing⁴. The retrieval and characterization of microorganisms from ancient halite crystals^5,6 suggests that it might be possible to locate their remains as biomarkers or even living cells from evaporites sampled from extraterrestrial environments. However, before this is possible, techniques for the detection of bacterial cells or biomolecules in halite and other evaporite crystals need further refining. Specifically, contamination must be minimized and quantified during the microbial analysis of such crystals. Aseptic techniques that allow for the direct extraction of fluid brines from micron to millimeter size inclusions significantly reduce the possibility for contamination. However, even with extreme precautions, the possibility for contamination cannot be entirely eliminated, particularly when culture-based methods are employed. We have elicited native fluorescence from a variety of biomolecules, including the aromatic amino acids and nucleic acids, by laser excitation at 248 and 224 nm from haloarchaea and haloarchaea residues trapped in halite. Energy to each sample, (positive control crystals with Halobacteria salinarum and bacteria-free negative control crystals), was 80 microwatts at 224 nm and 25 microwatts at 248 nm. A 30 s exposure of the inclusions within the positive control elicited easily detectable fluorescence while there was no response from the negative control crystals during the same exposure. Analysis of halite crystals sampled from the Waste Isolation Pilot Plant, Carlsbad, New Mexico yielded similar results. To minimize microbial damage from the high-energy 224-248 nm beams and to make the technique more widely available to the scientific community, we have examined the possibility of using a standard epi-fluorescent microscope for similar purposes. We have elicited a native fluorescence response from microscopic eukaryotes in rapid scanning, low magnification mode employing 365 nm excitation and are optimizing the visualization of prokaryotes with this system. Aseptic identification of epifluorescent biosignatures in evaporite inclusions would be of significant utility for planetary protection and preliminary screening protocols during a Mars sample return mission.

The Maillard reaction was studied from a prebiotic point of view. We have shown that the Maillard reaction between ribose and common amino acids occurs readily in the solid state at 65°C. The C-13 NMR spectra of the solid insoluble Maillard products of ribose and serine, or alanine or isoleucine were compared to the spectrum of the insoluble organic carbon on Murchison.

Desert varnish and silica rock coatings have perplexed investigators since Humboldt and Darwin. They are found in arid regions and deserts on Earth but the mechanism of their formation remains challenging (see Perry et al. this volume). One method of researching this is to investigate natural coatings, but another way is to attempt to produce coatings in vitro. Sugars, amino acids, and silicic acid, as well as other organic and (bio)organic compounds add to the complexity of naturally forming rock coatings. In the lab we reduced the complexity of the natural components and produced hard, silica coatings on basaltic chips obtained from the Mojave Desert. Sodium silicate solution was poured over the rocks and continuously exposed to heat and/or UV light. Upon evaporation the solutions were replenished. Experiments were performed at various pH's. The micro-deposits formed were analyzed using optical, SEM-EDAX, and electron microprobe. The coatings formed are similar in hardness and composition to silica glazes found on basalts in Hawaii as well as natural desert varnish found in US southwest deserts. Thermodynamic mechanisms are presented showing the theoretical mechanisms for overcoming energy barriers that allow amorphous silica to condense into hard coatings. This is the first time synthetic silica glazes that resemble natural coatings in hardness and chemical composition have been successfully reproduced in the laboratory, and helps to support an inorganic mechanism of formation of desert varnish as well as manganese-deficient silica glazes.

Desert varnish is a black, manganese-rich rock coating that is widespread on Earth. The mechanism underlying its formation, however, has remained unresolved. We present here new data and an associated model for how desert varnish forms, which substantively challenges previously accepted models. We tested both inorganic processes (e.g. clays and oxides cementing coatings) and microbial methods of formation. Techniques used in this preliminary study include SEM-EDAX with backscatter, HRTEM of focused ion beam prepared (FIB) wafers and several other methods including XRPD, Raman spectroscopy, XPS and Tof-SIMS. The only hypothesis capable of explaining a high water content, the presence of organic compounds, an amorphous silica phase (opal-A) and lesser quantities of clays than previously reported, is a mechanism involving the mobilization and redistribution of silica. The discovery of silica in desert varnish suggests labile organics are preserved by interaction with condensing silicic acid. Organisms are not needed for desert varnish formation but Bacteria, Archaea, Eukarya, and other organic compounds are passively incorporated and preserved as organominerals. The rock coatings thus provide useful records of past environments on Earth and possibly other planets. Additionally this model also helps to explain the origin of key varnish and rock glaze features, including their hardness, the nature of the "glue" that binds heterogeneous components together, its layered botryoidal morphology, and its slow rate of formation.

Artificial neural networks patterned on fundamental neurological features of the human perceptual system have been shown to produce Bayesian probabilistic classifications of galaxies^1-3, identify biotic and abiotic alteration of subsurface basalts⁴, distinguish terrestrial fossils from their background rock matrix⁵, and detect areas of Archean hydrothermal alteration⁶. Data inputs for these classification tasks have varied from astronomical or high altitude images and spectra, to sub-micron resolution elemental abundances. However, Bayesian theory assumes an absence of statistical and interpretive ambiguity in a target signal, the antithesis of the problems facing remote and human exploration of extreme environments on Earth and extraterrestrial sites such as Mars, comets, and the icy moons of Jupiter and Saturn. Fundamental to our certainty about the classification of geobiological targets on Earth is a long scientific history of familiarization both with the geochemical evolution of our planet and the reliability and discriminating power of particular instruments. Reduction of the uncertainty associated with a putative extraterrestrial biosignature derived from a single probe is most often attempted by deploying a suite of instruments, each one interrogating distinct morphological and chemical phenomena in a target⁷. But understanding the relative weighting appropriate for merging disparate signals or distinct data sets is not a trivial issue⁸. And, as we have most recently seen in the case of ALH84001, strategies relying on the cumulative statistical power of multiple probes often crumble when subsequent review of abiotic physicochemical phenomena reveals even a single abiotic mechanism, no matter how improbable, capable of replicating the putative biotic signal. Finally, for extend extraterrestrial missions or work in remote environments on Earth, the fundamental "fewest moving parts" reliability rule must come into play. This communication highlights the minimum requirements for an astrobiological instrument suite for remote or human exploration of extreme environments both here on Earth and in our local and neighboring planetary systems. Critical items of concern include obtaining co-registered data characterizing target morphology, metabolism, and mobility; the face validity and familiarity of the instrumentation to the scientific community, and the choice of instrumentation sufficiently inexpensive and easy to use that it might find wide spread usage within the astrobiology community prior to mission deployment. Preliminary indications are that such an instrument can be implemented for a cost accessible to high school, college, and graduate students interested in geobiological and astrobiological research in extreme or hazardous environments.

We have constructed an active mid-infrared Fourier transform micro-spectrometer capable of analyzing mineralogy and organic chemistry of specimens in the field. While of great utility for terrestrial studies, the instrument has also been designed for potential use on future robotic missions to Mars. The device operates in the spectral range of 650 cm^-1 (15 µm) to 3800 cm^-1 (2.6 µm) and has a 4 cm^-1 spectral resolution. The spectrometer is coupled to a microscope yielding a spatial resolution on the sample of approximately one millimeter. Mounted to the spectrometer are two motors that allow for spatial scanning of the sample. Maximum scanning range in both X and Y directions is approximately 2.5 centimeters. During a recent field campaign (Jan-Feb. 2005), our instrument successfully detected cryptoendolithic microbial communities in the Dry Valleys of Antarctica. Colonized rocks of Beacon sandstone in the Battleship Promontory formation were examined non-invasively both from the surface and in cross-section. Samples characteristic of the various communities (lichen, cyanobacterial) were analyzed. Detection of C-H bands on the surface, indicative of possible biology below, was successful. Several organic functional groups, characteristic of microorganisms, were detected in both lichen and cyanobacterial-dominated communities. In addition, the vertical distribution of inorganic compounds suggests that the organisms may play an active role in rock weathering.

The paper starts from the fundamental of x-ray diffraction (i.e. the essential elements of the instruments, lattice and the measurement real conditions) to provide a consistent base of confidence on the achievable implementation of at distance controlled x-ray diffraction. Metrological approach to the calibration of x-ray diffraction measures and the use of uncertainty of the x-ray diffraction parameters is proposed here as an intermediate objective for real time sound interpretation of information and directive to impart from distance to the controlled diffractometers. The establishment of an extended network of diffractometers/laboratory (i.e the system acting as a reference for monitoring the calibration in several appropriate environment condition) is an other intermediate objective to engine the holistic learning of the whole system. Finally the basic hardware, the solution platform and the graphical user interface of the diffractometers is illustrated in detail to demonstrate that the at distance controlled diffractometers with robotic functioning features is a realistic achievable target.

Based on observations of seemingly hostile aqueous environments on earth, it is possible for lifeforms not only to evolve but to thrive in conditions that, by human standards, are extreme. Such lifeforms, typically termed "extremophiles" can, for example, live in the vicinity of deep water volcanic vents that are spewing superheated water laden with sulfur compounds at intense pressures. Since similar conditions may exist on Jupiter's moon Europa, there is widespread interest in developing an autonomous search-for-life capability that could be deployed in aqueous, extraterrestrial environments. As one step toward this goal, the DEep Phreatic THermal eXplorer (DEPTHX) is a NASA Astrobiology Science and Technology for Exploring Planets (ASTEP) project to design, develop and field-test a robotic vehicle to explore such environments. The principal astrobiological science objective of DEPTHX is to develop an advanced methodology and protocol for the discrimination of microbial life in a sub-aqueous environment. Implementation requires the design, development, and demonstration of a fully autonomous architecture for intelligent biological sample detection and collection, whereby the robotic device will be capable of performing the following functions: 1. Deep hydrothermal springs will be mapped with great accuracy in three dimensions. 2. Data will be acquired from a hierarchical suite of on-board microbial life detection and sensors and processors and will be analyzed to determine whether life is present. 3. Specimens will be aseptically collected and returned for subsequent ex-situ laboratory analysis preserved under ambient conditions. The paper describes current progress toward these objectives, with an emphasis on the analysis of data acquired from the life sensors for the purpose of detecting lifeforms.

Single ≤1 kJ pulses from a high-power laser are focused into molecular gases to create large laser sparks. This provides a unique way to mimic the chemical effects of high-energy-density events in planetary atmospheres (cometary impact, lightning) matching the natural energy-density, its spatio-temporal evolution and plasma-volume scaling of such events in a fully-controlled laboratory environment. Some chemical reactions initiated by laser-induced dielectric breakdown (LIDB) in both pure molecular gases and mixtures related to the chemical evolution of the Earth's early atmosphere were studied. Most of the experiments were carried out in a static gas cell. However, an initial series of experiments was also performed with a gas-puff target placed within a vacuum interaction chamber. Under these dynamic conditions the hot core of a laser spark can be directly investigated.

We suggest that organic matter transmission based on diamagnetic expel of superconductor from magnetic fields, force of magnetic levitation, can be responsible for simplest life propagation in outer space. This mechanism can account for discoveries of complex organic molecules in interstellar environment. Survey of literature shows convincingly that generally accepted theories predict superconductivity of some organic molecules and numerous references to experimental data also testify to this possibility. The received results are based on the recent discovery of the superconducting origin of the rings of Saturn made by the author [41, 42].

We review and re-examine the idea that life emerged by a quantity-to-quality transition of the abiotic matter. This idea was originally proposed by the dialectical materialists, who are the proponents of the materialistic approach to the Hegel's laws of dialectics. We propose in this paper that the universal feature of the quantity-to-quality transitions is a change in the organization of the system. We also discuss Jean-Paul Sartre's view on the application of the laws of dialectics to the nature and to the origins of life.

The ALICE instrument is a lightweight (4.4 kg), low-power (4.4 W) imaging spectrograph that is planned to fly aboard the New Horizons mission to Pluto/Charon and the Kuiper Belt. Its primary job is to detect a variety of important atomic and molecular species in Pluto's atmosphere, and to determine their relative abundances as a function of altitude so that a complete picture of Pluto's atmospheric composition and structure can be determined for the first time. ALICE would also be used to search for an atmosphere around Pluto's moon, Charon, as well as the Kuiper Belt Objects (KBOs) that New Horizons hopes to fly by after Pluto-Charon. The New Horizons ALICE design, based on the Rosetta ALICE instrument design now en route to Comet 67P/ Churyumov-Gerasimenko aboard the European Space Agency's Rosetta spacecraft, incorporates an off-axis telescope feeding a Rowland-circle spectrograph with a 520-1870 Å spectral passband, a spectral point spread function of 3-6 Å FWHM, and an instantaneous spatial field-of-view of 6 degrees. Two separate input apertures that feed the telescope allow for both airglow and solar occultation observations during the mission. The focal plane camera is an imaging microchannel plate (MCP) double delay-line detector with dual solar-blind opaque photocathodes (KBr and CsI) and a focal surface that matches the 15-cm diameter Rowland-circle. Data taking modes include both histogram and pixel list exposures. We describe the scientific objectives of ALICE as well as the design, build, and environmental testing results of the flight model.

We describe the radiometric performance and calibration results of the New Horizons' ALICE flight model. This ALICE is a lightweight (4.4 kg), low-power (4.4 W), ultraviolet spectrograph based on the ALICE instrument now in flight aboard the European Space Agency's Rosetta spacecraft. Its primary job will be to detect a variety of important atomic and molecular species in Pluto's atmosphere, and to determine their relative abundances so that a complete picture of Pluto's atmospheric composition can be determined for the first time. ALICE will also be used to search for an atmosphere around Pluto's moon, Charon, as well as the Kuiper Belt Objects (KBOs) New Horizons hopes to fly by after Pluto-Charon. Detailed radiometric performance results of the ALICE flight model are presented and discussed.

The Lyman Alpha Mapping Project (LAMP) is an ultraviolet imaging spectrograph recently selected for NASA's Lunar Reconnaissance Orbiter (LRO) mission. Its main objectives are to (i) identify and localize exposed water frost in permanently shadowed regions (PSRs), (ii) characterize landforms and albedos in PSRs, (iii) demonstrate the feasibility of using natural starlight and sky-glow illumination for future lunar surface mission applications, and (iv) characterize the lunar atmosphere and its variability. The LAMP UV spectrograph will accomplish these objectives by measuring the signal reflected from the nightside lunar surface and in PSRs using both the interplanetary HI Lyman-α sky-glow and FUV starlight as light sources. Both these light sources provide fairly uniform, but faint, illumination (e.g., the reflected Lyman-α signal is expected to be ~10 R). Thanks to LAMP's sensitivity, by the end of the 1-year LRO mission the SNR for a Lyman-α albedo map will be >100 in polar regions exceeding 1 km² (and >15 for 100×100 m² polar regions), allowing the characterization of subtle compositional and structural features. The LAMP instrument is based on the flight-proven ALICE series of spectrographs that are flying on Rosetta and built for flight on NASA's New Horizons Pluto-Kuiper Belt Mission.

Remote observations from the Earth orbiting Chandra X-ray Observatory and the XMM-Newton Observatory have shown the the Jovian system is a rich and complex source of x-ray emission. The planet's auroral zones and its disk are powerful sources of x-ray emission, though with different origins. Chandra observations discovered x-ray emission from the Io plasma torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from the moons is due to bombardment of their surfaces by highly energetic magnetospheric protons, and oxygen and sulfur ions, producing fluorescent x-ray emission lines from the elements in their surfaces against an intense background continuum. Although very faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around the icy Galilean moons would provide a detail mapping of the elemental composition in their surfaces. Here we examine the necessary characteristics of such an instrument and the challenges it would face in the extreme radiation environment in which it would have to survive and operate. Such an instrument would have the ultimate goal of providing detailed high-resolution maps of the elemental abundances of the surfaces of Jupiter's icy moons and Io, as well as detailed study of the x-ray mission from the Io plasma torus, Jupiter's auroral zones, and the planetary disk.

We report the first efforts to characterize a laser desorption and thermal emission spectroscopic technique that could be used to detect and analyze the abundances of organic and inorganic compounds in the surfaces of Jupiter's icy moons. Based on the literature, an infrared laser near 3.1 μm at a moderate fluence 120 mJ/cm² may desorb the compounds in the ice surface into the gas phase through an efficient explosive phase-transition process. The desorbed compounds, which are much warmer than the ice, can be analyzed by monitoring their IR thermal emission spectra against the colder icy surface by use of an IR spectrometer. However, there appears to have some discrepancies in the literature on the exact threshold fluence for desorption. We have conducted experiments to determine the threshold fluence for the laser desorption of ice by use of a sensitive photoacoustic spectroscopy technique. Our results suggest that the threshold fluence near 3.1 μm, at the peak of optical absorption of ice, is close to 120 mJ/cm², as compared to some other higher values being reported. In addition, our data shows a delay time of about 24 μs or longer for an explosive removal of a layer of the ice surface after the irradiation of a laser pulse. Implications for mission and instrument design are discussed.

The LOng-Range Reconnaissance Imager (LORRI) is an instrument that was designed, fabricated, and qualified for the New Horizons mission to the outermost planet Pluto, its giant satellite Charon, and the Kuiper Belt, which is the vast belt of icy bodies extending roughly from Neptune's orbit out to 50 astronomical units (AU). New Horizons is being prepared for launch in January 2006 as the inaugural mission in NASA's New Frontiers program. This paper provides an overview of the efforts to produce LORRI. LORRI is a narrow angle (field of view=0.29°), high resolution (instantaneous field of view = 4.94 μrad), Ritchey-Chretien telescope with a 20.8 cm diameter primary mirror, a focal length of 263 cm, and a three lens field-flattening assembly. A 1024 x 1024 pixel (optically active region), back-thinned, backside-illuminated charge-coupled device (CCD) detector (model CCD 47-20 from E2V Technologies) is located at the telescope focal plane and is operated in standard frame-transfer mode. LORRI does not have any color filters; it provides panchromatic imaging over a wide bandpass that extends approximately from 350 nm to 850 nm. A unique aspect of LORRI is the extreme thermal environment, as the instrument is situated inside a near room temperature spacecraft, while pointing primarily at cold space. This environment forced the use of a silicon carbide optical system, which is designed to maintain focus over the operating temperature range without a focus adjustment mechanism. Another challenging aspect of the design is that the spacecraft will be thruster stabilized (no reaction wheels), which places stringent limits on the available exposure time and the optical throughput needed to accomplish the high-resolution observations required. LORRI was designed and fabricated by a combined effort of The Johns Hopkins University Applied Physics Laboratory (APL) and SSG Precision Optronics Incorporated (SSG).

The LOng-Range Reconnaissance Imager (LORRI) is a panchromatic imager for the New Horizons Pluto/Kuiper belt mission. New Horizons is being prepared for launch in January 2006 as the inaugural mission in NASA's New Frontiers program. This paper discusses the calibration and characterization of LORRI. LORRI consists of a Ritchey-Chretien telescope and CCD detector. It provides a narrow field of view (0.29°), high resolution (pixel FOV = 5 μrad) image at f/12.6 with a 20.8~cm diameter primary mirror. The image is acquired with a 1024 x 1024 pixel CCD detector (model CCD 47-20 from E2V). LORRI was calibrated in vacuum at three temperatures covering the extremes of its operating range (-100°C to +40°C for various parts of the system) and its predicted nominal temperature in-flight. A high pressure xenon arc lamp, selected for its solar-like spectrum, provided the light source for the calibration. The lamp was fiber-optically coupled into the vacuum chamber and monitored by a calibrated photodiode. Neutral density and bandpass filters controlled source intensity and provided measurements of the wavelength dependence of LORRI's performance. This paper will describe the calibration facility and design, as well as summarize the results on point spread function, flat field, radiometric response, detector noise, and focus stability over the operating temperature range. LORRI was designed and fabricated by a combined effort of The Johns Hopkins University Applied Physics Laboratory (APL) and SSG Precision Optronics. Calibration was conducted at the Diffraction Grating Evaluation Facility at NASA/Goddard Space Flight Center with additional characterization measurements at APL.

The instrument named Ralph is a visible/NIR imager and IR hyperspectral imager that would fly as one of the core instruments on New Horizons, NASA's mission to the Pluto/Charon system and the Kuiper Belt. It is a compact, power efficient, and robust instrument with excellent imaging characteristics and sensitivity, and is well suited to this longduration flyby reconnaissance mission.

Early greek philosophers laid the philosophical foundations of the distinction between bio and abiogenesis, when they debated organic and non-organic explanations for natural phenomena. Plato and Aristotle gave organic, or purpose-driven explanations for physical phenomena, whereas the materialist school of Democritus and Epicurus gave non-organic, or materialist explanations. These competing schools have alternated in popularity through history, with the present era dominated by epicurean schools of thought. Present controversies concerning evidence for exobiology and biogenesis have many aspects which reflect this millennial debate. Therefore this paper traces a selected history of this debate with some modern, 20th century developments due to quantum mechanics. It finishes with an application of quantum information theory to several exobiology debates.