ALBERT

Description: Research Articles J. Chela-Flores, A. Cicuttin, M.L. Crespo, C. Tuniz, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 427-434 Abstract

Description: Research Articles Tianzhi Li, De Chang, Huiwen Xu, Jiapeng Chen, Longxiang Su, Yinghua Guo, Zhenhong Chen, Yajuan Wang, Li Wang, Junfeng Wang, Xiangqun Fang, Changting Liu, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 435-444 Abstract

Description: Research Articles Jacopo Farinato, Carlo Baffa, Andrea Baruffolo, Maria Bergomi, Luca Carbonaro, Alexis Carlotti, Mauro Centrone, Johanan Codona, Marco Dima, Simone Esposito, Daniela Fantinel, Giancarlo Farisato, Wolfgang Gaessler, Emanuele Giallongo, Davide Greggio, Philip Hinz, Franco Lisi, Demetrio Magrin, Luca Marafatto, Fernando Pedichini, Enrico Pinna, Alfio Puglisi, Roberto Ragazzoni, Bernardo Salasnich, Marco Stangalini, Christophe Verinaud, Valentina Viotto, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 365-373 Abstract

Description: Research Articles Paul A. Mason, Jorge I. Zuluaga, Pablo A. Cuartas-Restrepo, Joni M. Clark, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 391-400 Abstract

Description: Review Articles Amri Wandel, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 511-516 Abstract

Description: Research Articles Carlo Canepa, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 497-504 Abstract

Description: Research Articles Jeff R. Kuhn, Svetlana V. Berdyugina, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 401-410 Abstract

Description: Research Articles Wesley A. Traub, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 359-363 Abstract

Description: Research Articles Duncan H. Forgan, Alexander Mead, Charles S. Cockell, John A. Raven, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 465-478 Abstract

Description: Research Articles Marina G. Martynova, Sergej V. Shabelnikov, Olga A. Bystrova, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 489-495 Abstract

Description: Research Articles Yu Komatsu, Masayuki Umemura, Mitsuo Shoji, Megumi Kayanuma, Kazuhiro Yabana, Kenji Shiraishi, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 505-510 Abstract

Description: Review Articles Elif Koeksoy, Maximilian Halama, Kurt O. Konhauser, Andreas Kappler, International Journal of Astrobiology , Volume 15 Issue 03 , pp 205-217 Abstract

Description: Research Articles Bettina E. Schirrmeister, Patricia Sanchez-Baracaldo, David Wacey, International Journal of Astrobiology , Volume 15 Issue 03 , pp 187-204 Abstract

Description: Research Articles Chaitanya Giri, Christopher P. McKay, Fred Goesmann, Nadine Schäfer, Xiang Li, Harald Steininger, William B. Brinckerhoff, Thomas Gautier, Joachim Reitner, Uwe J. Meierhenrich, International Journal of Astrobiology , Volume 15 Issue 03 , pp 231-238 Abstract

Description: Editorial Jan-Peter Duda, Joachim Reitner, International Journal of Astrobiology , Volume 15 Issue 03 , pp 161-163 Abstract

Description: Research Articles Blanca Rincón-Tomás, Bahar Khonsari, Dominik Mühlen, Christian Wickbold, Nadine Schäfer, Dorothea Hause-Reitner, Michael Hoppert, Joachim Reitner, International Journal of Astrobiology , Volume 15 Issue 03 , pp 219-229 Abstract

Description: Research Articles W. Goetz, W. B. Brinckerhoff, R. Arevalo, C. Freissinet, S. Getty, D. P. Glavin, S. Siljeström, A. Buch, F. Stalport, A. Grubisic, X. Li, V. Pinnick, R. Danell, F. H. W. van Amerom, F. Goesmann, H. Steininger, N. Grand, F. Raulin, C. Szopa, U. Meierhenrich, J. R. Brucato, International Journal of Astrobiology , Volume 15 Issue 03 , pp 239-250 Abstract

Description: Research Articles H. Mißbach, J.-P. Duda, N.K. Lünsdorf, B.C. Schmidt, V. Thiel, International Journal of Astrobiology , Volume 15 Issue 03 , pp 165-175 Abstract

Description: Research Articles A. Montinaro, H. Strauss, International Journal of Astrobiology , Volume 15 Issue 03 , pp 177-185 Abstract

Description: 〈div data-abstract-type="normal"〉〈p〉This paper examines and deconstructs the Rio Scale, focusing primarily on the recently published Rio Scale 2.0 concept, from the perspective of a social scientist. I argue that although there is value in developing tools to help astronomers and other scientists communicate their perceptions about the significance of a contact event to the media and the general public, the Rio Scale 2.0 remains problematic conceptually and, thus, does not represent a robust method for assessing or communicating the import of a valid contact. Therefore, it should not be used as a method for informing the media or the general public about scenarios that involve the detection of valid signals suggesting the existence of extraterrestrial intelligence.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉About 400 subglacial lakes are known from Antarctica. The question of whether life unique of subglacial lakes exists has been paramount since their discovery. Despite frequent evidence of microbial life mostly from accretion ice, subglacial lakes are characterized by physiologically hostile conditions to metazoan life, as we know it. Pure water (salinity ≤0.4–1.2%), extreme cold (−3°C), high hydrostatic pressure, areas of limited or no oxygen availability and permanent darkness altogether require physiological adaptations to these harsh conditions. The record of gene sequences including some associated with hydrothermal vents does foster the idea of metazoan life in Lake Vostok. Here, we synthesize the physico-chemical environment surrounding sub-glacial lakes and potential sites of hydrothermal activity and advocate that the physico-chemical stability found at these sites may be the most likely sites for metazoan life to exist. The unique conditions presented by Lake Vostok may also offer an outlook on life to be expected in extra-terrestrial subglacial environments, such as on Jupiter's moon Europa or Saturn's moon Enceladus.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The maximum height trees can grow on Earth is around 122–130 m. The height is constrained by two factors: the availability of water, and where water is not limiting, the pressure available to drive the column of water along the xylem vessels against the pull of gravity (cohesion tension). In turn the height of trees impacts the biodiversity of the environment in a number of ways. On Earth the largest trees are found in maritime temperate environments along the Pacific Northwest coasts of northern California and southern Oregon. These forests provide a large number of secondary habitats for species and serve as moisture pumps that return significant volumes of water to the lower atmosphere. In this work, we apply simple mathematical rules to illustrate how super-terran planets will have significantly smaller trees, with concomitant effects on the habitability of the planet. We also consider the impact of varying tree height on climate models.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Is our current concept of sustainable development too focused on our planet? Do we need a new conception of sustainability? The recent call for an 'ethics of planetary sustainability' by A. Losch may be understood as promoting an affirmative answer to this question. This essay analyses and assesses the introduction of a new concept of sustainability from the perspective of conceptual engineering. The central question is whether this new concept, which I call ‘transplanetary sustainability’, may improve our thinking, and, indirectly, our practices. I argue that a new notion of transplanetary sustainability advantageously points to considerations that matter from a moral point of view. It may also help us to be more exact and consistent in our moral thinking. At the same time, there are serious doubts as to how fundamental the concept of sustainability as such is from a theoretical perspective since it does not figure in prominent moral theories. Furthermore, in view of possible extraterrestrial beings that deserve to be taken into account from a moral point of view, the proposed revision of the concept may reach less than required. Nevertheless, since sustainability has had an impressive career in international politics, it is practically speaking important that sustainability be conceived such that outer space is taken into account.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The Stanley Miller experiment suggests that amino acid-based life is ubiquitous in our universe, although its varieties will not have followed the particular, highly contingent and path-dependent, evolutionary trajectory found on Earth. Are many alien organisms likely to be individually conscious in ways we would recognize? Almost certainly. Will alien consciousness require a ‘sleep cycle’? A strong argument suggests it will. Can some species develop analogs to culture and high-order technology? Less likely, but still fairly probable. If so, will we be able to communicate with them? Only on a basic level, and only with profound difficulty. The reasoning is fairly direct and involves convolution of a learned heritage system with individual and collective consciousness.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The astonishing capability of life to adapt to extreme conditions has provided a new perspective on what ‘habitable’ means. On Earth extremophiles thrive in hostile habitats, such as hot and cold deserts or Antarctic sub-glacial lakes considered as Earth analogues of Mars and icy moons of Jupiter and Saturn. Recently desert cyanobacteria were exposed to ground-based simulations of space and Martian conditions and to real space and Martian conditions simulated in low Earth orbit using facilities attached outside the International Space Station. When exposure to such conditions does not exceed repair capabilities, more data are available regarding the physico-chemical constraints that life can withstand. When the accumulated damage exceeds the survival potential, the persistence of biomarkers contributes to the search for life elsewhere. Knowledge concerning the endurance of desert cyanobacteria under space and Martian conditions contributes to the development of life support systems.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Many rocky exoplanets are heavier and larger than the Earth and have higher surface gravity. This makes space-flight on these worlds very challenging because the required fuel mass for a given payload is an exponential function of planetary surface gravity, exp(g〈span〉0〈/span〉). We find that chemical rockets still allow for escape velocities on Super-Earths up to 10× Earth mass. More massive rocky worlds, if they exist, would require other means to leave the planet, such as nuclear propulsion. This is relevant for space colonization and the search for extraterrestrial intelligence.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉We suggest testing S isotopes as biomarkers for Mars. An analogous robust biosignature has recently been proposed for the forthcoming exploration of the icy surface of Europa, and in the long term for the exploration of the surfaces of other icy moons of the outer solar system. We discuss relevant instrumentation for testing the presence of life itself in some sites, whether extinct or extant in order to complement a set of other independent biosignatures. We pay special attention to the possible early emergence of sulphate-metabolizing microorganisms, as it happened on the early Earth. Fortunately, possible sites happen to be at likely landing sites for future missions ExoMars and Mars 2020, including Oxia Planum and Mawrth Vallis. We suggest how to make additional feasible use of the instruments that have already been approved for future missions. With these instruments, the proposed measurements can allow testing S isotopes on Mars, especially with the Mars Organic Molecule Analyzer.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Formaldehyde is a precursor of sugars, which are compounds essential in all forms of life and a necessary molecule for prebiotic processes. This work focuses on evaluating the stability of formaldehyde exposed to a high radiation field simulating prebiotic conditions on primitive Earth, such as the ocean or shallow waters. Formaldehyde may have been formed from reactions in the atmosphere and from rainout processes reached water bodies. In our experiments, we employed γ radiation and found that formaldehyde was labile towards radiation and decomposed even at low irradiation doses due to the fact that aldehyde/hydrate groups present in formaldehyde structure are very reactive under irradiation. However, after exposing this molecule to several doses of irradiation, we detected the formation of formic acid and glycolaldehyde – both of which are of prebiotic interest. We also observed formaldehyde regeneration by one of its radiolytic products: formic acid.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The number of people able to end Earth's technical civilization has heretofore been small. Emerging dual-use technologies, such as biotechnology, may give similar power to thousands or millions of individuals. To quantitatively investigate the ramifications of such a marked shift on the survival of both terrestrial and extraterrestrial technical civilizations, this paper presents a two-parameter model for civilizational lifespans, i.e. the quantity 〈span〉L〈/span〉 in Drake's equation for the number of communicating extraterrestrial civilizations. One parameter characterizes the population lethality of a civilization's biotechnology and the other characterizes the civilization's psychosociology. 〈span〉L〈/span〉 is demonstrated to be less than the inverse of the product of these two parameters. Using empiric data from PubMed to inform the biotechnology parameter, the model predicts human civilization's median survival time as decades to centuries, even with optimistic psychosociological parameter values, thereby positioning biotechnology as a proximate threat to human civilization. For an ensemble of civilizations having some median calculated survival time, the model predicts that, after 80 times that duration, only one in 10〈span〉24〈/span〉 civilizations will survive – a tempo and degree of winnowing compatible with Hanson's ‘Great Filter.’ Thus, assuming that civilizations universally develop advanced biotechnology, before they become vigorous interstellar colonizers, the model provides a resolution to the Fermi paradox.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉 〈p〉According to the Kardashev scale, likely extraterrestrial civilizations above Type-I might use natural energy sources of the Universe, which is also true for transmitting their signals out to distances. A variety of studies have shown that radio pulsars are most likely candidates for this. First, the current study examined how the radio beams of pulsars scan across their environment. Later when the radio beams of pulsars have been modulated, a network model has been proposed on how many habitable planets possible to be home for other assumed advanced civilizations could be reached. It has been found that size of each pulsar's broadcast network depends on the inclination angle. If a civilization controls multiple pulsars, it could comb a considerable fraction of their own celestial sphere and pulsars share their signals in a decentralized fashion as in the mail servers. Moreover, it is briefly cited how beam-modulating mechanisms can be built and searched around pulsars.〈/p〉 〈p〉〈span〉Highlights〈/span〉〈/p〉 〈ul〉 〈li〉•  It has been shown how pulsars would behave like beacons only when they have been used by modulating their radio signals.〈/li〉 〈li〉•  It has also been indicated how each pulsar could constitute an increasingly growing broadcast network by sweeping geometries and in what way it would emerge as number of controlled pulsars increases.〈/li〉 〈li〉•  It has been interpreted how a modulation mechanism could be established and searched under basic physical principles.〈/li〉 〈/ul〉 〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉In the previous paper (Whitmire 2017; hereafter Paper I) arguments were given which suggest that the 〈span〉typical〈/span〉 technological species is short-lived and that their demise coincides with the extinction of their planetary biosphere. This conclusion is based on two observations and one primary assumption. The observations are: (1) Our own technological species is the first such species to evolve on Earth and (2) we are early in the potential evolution of a technological species. The primary assumption is that we are a typical member (in age) of the reference class of 〈span〉all〈/span〉 extant technological species in the universe. In this Letter, I thoroughly discuss the anthropic selection effect that the predicted lifetime of the typical technological species would most likely first be made when a technological species is young, thus guaranteeing a predicted short lifetime, regardless of the actual typical lifetime. I argue here that this selection effect is equivalent to narrowly redefining the reference class to be 〈span〉only〈/span〉 early technological species and, although true, it is a logical tautology, correct by definition and does not invalidate the application of the Principle of Mediocrity assumption to the expanded reference class of 〈span〉all〈/span〉 technological species, as was done in Paper I. Several simple analogies are given to illustrate this point.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Almost all living organisms on Earth utilize the same 20 amino acids to build their millions of different proteins, even though there are hundreds of amino acids naturally occurring on Earth. Although it is likely that both the prebiotic and the current environment of Earth shaped the selection of these 20 proteinogenic amino acids, environmental conditions on extraterrestrial planets and moons are known to be quite different than those on Earth. In particular, the surfaces of planets and moons such as Mars, Europa and Enceladus have a much greater flux of UV and gamma radiation impacting their surface than that of Earth. Thus, if life were to have evolved extraterrestrially, a different lexicon of amino acids may have been selected due to different environmental pressures, such as higher radiation exposure. One fundamental property an amino acid must have in order to be of use to the evolution of life is relative stability. Therefore, we studied the stability of three different proteinogenic amino acids (tyrosine, phenylalanine and tryptophan) as compared with 20 non-proteinogenic amino acids that were structurally similar to the aromatic proteinogenic amino acids, following ultraviolet (UV) light (254, 302, or 365 nm) and gamma-ray irradiation. The degree of degradation of the amino acids was quantified using an ultra-high performance liquid chromatography-mass spectrometer (UPLC-MS). The result showed that many non-proteinogenic amino acids had either equal or increased stability to certain radiation wavelengths as compared with their proteinogenic counterparts, with fluorinated phenylalanine and tryptophan derivatives, in particular, exhibiting enhanced stability as compared with proteinogenic phenylalanine and tryptophan amino acids following gamma and select UV irradiation.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The potential of a mass asteroid impact on Earth to disturb the chemosynthetic communities at global scale is discussed. Special emphasis is made on the potential influence on anammox communities and their implications in the nitrogen biogeochemical cycle. According to our preliminary estimates, anammox communities could be seriously affected as a consequence of global cooling and the large process of acidification usually associated with the occurrence of this kind of event. The scale of affectations could vary in a scenario like the Chicxulub as a function of the amount of soot, depth of the water column and the deposition rate for sulphates assumed in each case. The most severe affectations take place where the amount of soot and sulphates produced during the event is higher and the scale of time of settlements for sulphates is short, of the order of 10 h. In this extreme case, the activity of anammox is considerably reduced, a condition that may persist for several years after the impact. Furthermore, the impact of high levels of other chemical compounds like sulphates and nitrates associated with the occurrence of this kind of event are also discussed.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉〈span〉Candida lusitaniae〈/span〉 and 〈span〉C. guilliermondii〈/span〉 are perfect model organisms for the study of 〈span〉Candida〈/span〉 genera behaviour in various conditions. Both of them are rare pathogens capable to cause candidiasis in the patients with weakened immune system and can undergo morphology switches related to the increased antifungal drug resistance. 〈span〉Candida〈/span〉 genera yeasts are able to inhabit diverse range of ecological niches including space ships and space stations. During the long-term expeditions, astronauts are affected by various factors that can change the state immune system. In such conditions, the commensal usually non-pathogenic microorganisms can spread through the body of the host and cause infections. Weakened immune system and limited use of drugs in spaceships promote the search of the alternative methods for the biocontrol of microorganisms. Several studies demonstrate that microorganisms are altering their gene expression, physiology, morphology, pathogenicity and evolving resistance to the antifungals under microgravity conditions. Our research indicated that switch to the pseudohyphae morphology leads up 30-fold increased resistance to amphotericin B in 〈span〉C. lusitaniae〈/span〉 and 〈span〉C. guilliermondii〈/span〉. Cultivation of yeasts in rotary cell culture system (RCCS) is related to the altered cell growth and resistance to the antifungal treatment. Our results showed that growth in the RCCS led to the extreme increase in cell resistance to amphotericin B as compared with the standard growth conditions. In our research, we applied electroporation for the biocontrol of two 〈span〉Candida〈/span〉 species. 〈span〉C. lusitaniae〈/span〉 and 〈span〉C. guilliermondii〈/span〉 cells grown in RCCS exhibited significantly increased survivability after pulsed electric field (PEF) treatment in comparison with cells grown under routine conditions. We have shown that PEF bursts of 2.5–25 kV cm〈span〉−1〈/span〉 of 100 µs × 8 duration display a dose-dependent permeabilization of both studied 〈span〉Candida〈/span〉 species. Our research indicated that budding cells and pseudohyphae morphology cells, with increased resistance to amphotericin B, can be effectively inactivated after applying PEF higher than 15 kV cm〈span〉−1〈/span〉.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉In this paper, we connect ideas of the astrobiological and ecological schools to quantify habitability. We show how habitability indexes, devised using the astrobiologically inspired Quantitative Habitability Theory (QHT), can be embedded into ecological models of trophic levels. In particular, we address the problem of spatial-temporal scales. It turns out that the versatility of QHT allows to treat spatial and temporal scales typical of ecological studies. As a habitability index, we propose a new version of our Aquatic Primary Habitability, devised by some of us and formerly applied to saltwater ecosystems (both ocean and coastal) and now applied to freshwater. Although the aim of the paper is to outline the methodology rather than realism, initial steps for parameterization are considered for lakes of South-Central Chile.〈/p〉〈/div〉

Description: Editorial Nader Haghighipour, International Journal of Astrobiology , Volume 14 Special Issue 02 , pp 143-143 Abstract

Description: Research Articles Andrej Prša, Annie Robin, Thomas Barclay, International Journal of Astrobiology , Volume 14 Special Issue 02 , pp 165-172 Abstract

Description: Research Articles Adrian L. Melott, Ilya G. Usoskin, Gennady A. Kovaltsov, Claude M. Laird, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 375-378 Abstract

Description: Research Articles Charles S. Cockell, Claire Cousins, Paul T. Wilkinson, Karen Olsson-Francis, Ben Rozitis, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 457-463 Abstract

Description: Research Articles Annette Brandt, Jean-Pierre de Vera, Silvano Onofri, Sieglinde Ott, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 411-425 Abstract

Description: Research Articles Fantucci Rosanna, Serra Romano, Kletetschka Gunther, Di Martino Mario, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 345-357 Abstract

Description: Research Articles A. García Muñoz, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 379-390 Abstract

Description: Research Articles T. Backhaus, R. de la Torre, K. Lyhme, J.-P. de Vera, J. Meeßen, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 479-488 Abstract

Description: Research Articles J. Jänchen, J. Meeßen, T.H. Herzog, M. Feist, R. de la Torre, J.-P.P. deVera, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 445-456 Abstract

Description: Research Articles Susanne Douglas, Meredith E. Perry, William J. Abbey, Zuki Tanaka, Bin Chen, Christopher P. McKay, International Journal of Astrobiology , Volume 14 Special Issue 03 , pp 517-526 Abstract

Description: Research Articles Rachana Sharma, Md. Asif Iqubal, null Kamaluddin, International Journal of Astrobiology , Volume 15 Issue 01 , pp 17-25 Abstract

Description: Research Articles Cyprien Verseux, Mickael Baqué, Kirsi Lehto, Jean-Pierre P. de Vera, Lynn J. Rothschild, Daniela Billi, International Journal of Astrobiology , Volume 15 Issue 01 , pp 65-92 Abstract

Description: Research Articles Svetlana V. Berdyugina, Jeff R. Kuhn, David M. Harrington, Tina Šantl-Temkiv, E. John Messersmith, International Journal of Astrobiology , Volume 15 Issue 01 , pp 45-56 Abstract

Description: Research Articles Sávio Torres de Farias, Thais Gaudêncio Rêgo, Marco V José, International Journal of Astrobiology , Volume 15 Issue 01 , pp 27-31 Abstract

Description: Editorial Sohan Jheeta, International Journal of Astrobiology , Volume 15 Issue 01 , pp 1-1 Abstract

Description: Research Articles R. Claudi, M. S. Erculiani, G. Galletta, D. Billi, E. Pace, D. Schierano, E. Giro, M. D'Alessandro, International Journal of Astrobiology , Volume 15 Issue 01 , pp 35-44 Abstract

Description: Research Articles Christos Kotakis, International Journal of Astrobiology , Volume 15 Issue 01 , pp 3-5 Abstract

Description: Research Articles S. Gill, P. Forterre, International Journal of Astrobiology , Volume 15 Issue 01 , pp 7-15 Abstract

Description: Research Articles Carlo Canepa, International Journal of Astrobiology , Volume 15 Issue 01 , pp 57-64 Abstract

Description: 〈div data-abstract-type="normal"〉〈p〉The deep subsurface of other planetary bodies is of special interest for robotic and human exploration. The subsurface provides access to planetary interior processes, thus yielding insights into planetary formation and evolution. On Mars, the subsurface might harbour the most habitable conditions. In the context of human exploration, the subsurface can provide refugia for habitation from extreme surface conditions. We describe the fifth Mine Analogue Research (MINAR 5) programme at 1 km depth in the Boulby Mine, UK in collaboration with Spaceward Bound NASA and the Kalam Centre, India, to test instruments and methods for the robotic and human exploration of deep environments on the Moon and Mars. The geological context in Permian evaporites provides an analogue to evaporitic materials on other planetary bodies such as Mars. A wide range of sample acquisition instruments (NASA drills, Small Planetary Impulse Tool (SPLIT) robotic hammer, universal sampling bags), analytical instruments (Raman spectroscopy, Close-Up Imager, Minion DNA sequencing technology, methane stable isotope analysis, biomolecule and metabolic life detection instruments) and environmental monitoring equipment (passive air particle sampler, particle detectors and environmental monitoring equipment) was deployed in an integrated campaign. Investigations included studying the geochemical signatures of chloride and sulphate evaporitic minerals, testing methods for life detection and planetary protection around human-tended operations, and investigations on the radiation environment of the deep subsurface. The MINAR analogue activity occurs in an active mine, showing how the development of space exploration technology can be used to contribute to addressing immediate Earth-based challenges. During the campaign, in collaboration with European Space Agency (ESA), MINAR was used for astronaut familiarization with future exploration tools and techniques. The campaign was used to develop primary and secondary school and primary to secondary transition curriculum materials on-site during the campaign which was focused on a classroom extra vehicular activity simulation.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Although we have learned much about the geological characteristics and history of Mars, the gaps in our knowledge certainly exceed what we understand. Martian meteorites, such as Northwest Africa (NWA) 6963, can be excellent materials for understanding the present and past of Mars, as part of the records of the planet's evolution is preserved in these extraterrestrial rocks. Micro X-ray fluorescence provided data, in which it was possible to verify the presence of Ca, P and Y elements, which are call attention because they were detected superimposed in certain regions. The way these elements were detected indicates the formation of minerals composed by the combination of these elements, such as, for example, Calcite (CaCO〈span〉3〈/span〉), Apatite [Ca〈span〉5〈/span〉(PO〈span〉4〈/span〉)〈span〉3〈/span〉(OH, F, Cl)], Merrilite [Ca〈span〉9〈/span〉NaMg (PO〈span〉4〈/span〉)〈span〉7〈/span〉] and Xenotime (YPO〈span〉4〈/span〉). These minerals are great indicators of aqueous environments. In general, the formation of these minerals is due to processes involving hydrothermal fluids or sources (〉100 °C). Some geological indications suggest that in the past there might have been a large amount of liquid water, which could have accumulated large reservoirs below the Martian surface. Thus, the laboratory study of Martian meteorites and interpretations of minerals present in these samples can contribute in a complementary way to the existing results of telescopic observations and/or missions of space probes as a strategy to indicate reservoirs of liquid water.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The detection of organic molecules that are indicative of past or present biological activity within the Solar System bodies and beyond is a key research area in astrobiology. Mars is of particular interest in this regard because of evidence of a (perhaps transient) warm and wet climate in its past. To date, space missions to Mars have primarily used pyrolysis technique to extract organic compounds from the Martian regolith, but it has not enabled a clear detection of unaltered native Martian organics. The elevated temperatures required for pyrolysis extraction can cause native Martian organics to react with perchlorate salts in the regolith, possibly resulting in the chlorohydrocarbons that have been detected by mass spectrometry, a commonly used 〈span〉in situ〈/span〉 technique for space applications. Supercritical carbon dioxide (SCCO〈span〉2〈/span〉) extraction technique is a powerful alternative to pyrolysis that may be capable of extracting and delivering unaltered native organic species to an analyser. In this study, we report the SCCO〈span〉2〈/span〉 extraction of unaltered amino acids (AAs) with simple laboratory analyses of extracts by capillary electrophoresis laser-induced fluorescence (CE/LIF) and liquid chromatography with mass spectrometry (LC/MS) techniques. The extraction efficiencies of several representative AAs using SCCO〈span〉2〈/span〉 with small amounts of pure water (~1–5%) as a co-solvent were determined. Glass beads were used as a model substrate to examine the effects of several experimental parameters and Johnson Space Center (JSC) Mars-1A Martian regolith simulant was used to study the effect of complex matrix on extraction efficiencies. With optimized experimental conditions (75C and 5% of water), extraction efficiencies from doped JSC Mars-1A were found to be ~40% for glycine, alanine and serine and ~10% for lysine. Extraction of native organics from undoped JSC Mars-1A suggests that SCCO〈span〉2〈/span〉/water solvent system can extract both organics extractable with pure SCCO〈span〉2〈/span〉 and those extractable with pure water. Additionally, species not extracted by either pure SCCO〈span〉2〈/span〉 or pure water were extracted with SCCO〈span〉2〈/span〉/water solvent. Despite the preliminary nature of this work, it paves the path for more comprehensive extraction studies of astrobiologically relevant samples with thorough analyses of resulting extracts.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉According to the Principle of Mediocrity, a cornerstone of modern cosmology, in the absence of any evidence to the contrary, we should believe that we are a typical member of an appropriately chosen reference class. If we assume that this principle applies to the reference class of all extant technological species, then it follows that other technological species will, like us, typically find that they are both the first such species to evolve on their planet and also that they are early in their potential technological evolution. Here we argue that this suggests that the typical technological species becomes extinct soon after attaining a modern technology and that this event results in the extinction of the planet's global biosphere.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Surface mineral crusts on Earth are highly diverse and usually, contain microbial life. Crusts constitute an attractive target to search for life: they require water for their formation, they efficiently entrap organic matter and are relatively easy to sample and process. They hold a record of life in the form of microbial remains, biomolecules and carbon isotope composition. A miniaturized Raman spectrometer is included in the ExoMars 2020 payload as it is sensitive to a range of photosynthetic pigments. Samples from the Haughton Impact Structure, Canadian High Arctic and others, shows the preservation of pigments in a range of crust types, especially supra-permafrost carbonate crusts and cryptogamic crusts. The Raman spectral signatures of these crusts are shown along with biomarker analysis to showcase these techniques prior to the ExoMars 2020 mission. Carotenoids and other photoprotective microbial pigments are identified in the Haughton surface crusts using Raman spectroscopy. Gas chromatography-mass spectrometry analyses show a distribution of fatty acids which are most likely from a cyanobacterial source. The successful demonstration of these analyses in the Haughton Impact structure shows the biosignature of surface mineral crusts can be easily extracted and provides an excellent target for sampling evidence of life on Mars.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉We numerically model the dynamics of the Enceladus plume ice grains and define our nominal plume model as having a particle size distribution 〈span〉n〈/span〉(〈span〉R〈/span〉) ~ 〈span〉R〈/span〉〈span〉−q〈/span〉 with 〈span〉q〈/span〉 = 4 and a total particulate mass rate of 16 kg s〈span〉−1〈/span〉. This mass rate is based on average plume brightness observed by Cassini across a range of orbital positions. The model predicts sample volumes of ~1600 µg for a 1 m〈span〉2〈/span〉 collector on a spacecraft making flybys at 20–60 km altitudes above the Enceladus surface. We develop two scenarios to predict the concentration of amino acids in the plume based on these assumed sample volumes. We specifically consider Glycine, Serine, α-Alanine, α-Aminoisobutyric acid and Isovaline. The first ‘abiotic’ model assumes that Enceladus has the composition of a comet and finds abundances between 2 × 10〈span〉−6〈/span〉 to 0.003 µg for dissolved free amino acids and 2 × 10〈span〉−5〈/span〉 to 0.3 µg for particulate amino acids. The second ‘biotic’ model assumes that the water of Enceladus's ocean has the same amino acid composition as the deep ocean water on Earth. We compute the expected captured mass of amino acids such as Glycine, Serine, and α-Alanine in the ‘biotic’ model to be between 1 × 10〈span〉−5〈/span〉 to 2 × 10〈span〉−5〈/span〉 µg for dissolved free amino acids and dissolved combined amino acids and about 0.0002 µg for particulate amino acids. Both models consider enhancements due to bubble bursting. Expected captured mass of amino acids is calculated for a 1 m〈span〉2〈/span〉 collector on a spacecraft making flybys with a closest approach of 20 km during mean plume activity for the given nominal particle size distribution.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Martian meteorites have valuable information about past geological processes on Mars. In this particular case, the sample used was the Martian meteorite Northwest Africa (NWA) 7397. The main objective was to conduct preliminary analyses of the sample that was able to provide mineralogical characteristics in a non-destructive way. These meteorite NWA 7397 analyses were performed using two analytical techniques, μRaman and μXRF. Through the techniques used it was possible to suggest the presence of chromite, ilmenite, magnetite and forsterite minerals. These minerals seem to have a correspondence to one another in relation to the process that formed them. Thus, the information generated by these analytical techniques can contribute significantly by providing information on the history of Mars in order to have relevance to the areas of Astrobiology and Planetary Sciences.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉We continue to investigate the binary system Kepler-16, consisting of a K-type main-sequence star, a red dwarf and a circumbinary Saturnian planet. As part of our study, we describe the system's habitable zone based on different climate models. We also report on stability investigations for possible Earth-mass Trojans while expanding a previous study by B. L. Quarles and collaborators given in 2012. For the climate models, we carefully consider the relevance of the system's parameters. Furthermore, we pursue new stability simulations for the Earth-mass objects starting along the orbit of Kepler-16b. The eccentricity distribution as obtained prefers values close to circular, whereas the inclination distribution remains flat. The stable solutions are distributed near the co-orbital Lagrangian points, thus enhancing the plausibility that Earth-mass Trojans might be able to exist in the Kepler-16(AB) system.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Prebiotic chemical evolution on the early Earth may have been driven in part by fluctuating environments, for example wet‒dry and temperature cycling in volcanic rock pools. Here, we describe the setup, operating principle and test applications of a newly developed ‘wet‒dry apparatus’ (WDA) designed to simulate such fluctuating environments. The WDA allows adjusting the duration of the cycles, the temperature during the wet and dry phases and the organic and mineral components, which are all key parameters in wet–dry simulations. The WDA's most important features, however, are (i) that it is automated, which means that long-time experiments are possible without the need for an operator and (ii) that the virtual absence of free oxygen in the early Earth's atmosphere at ground level can be simulated. Rigorously oxygen-free conditions were achieved by passing 99.999% nitrogen gas through two alkaline pyrogallol solutions in series, prior to entering the WDA. We used three chemical systems to test the WDA: (i) the amino acid glycine in the presence and absence of clay minerals, (ii) linoleic acid (an oxygen-sensitive amphiphile) with and without the mineral olivine, and (iii) alkaline pyrogallol solution. We observed that clay minerals greatly accelerated the decomposition of glycine under wet‒dry conditions. Glycine peptides were formed as minor products. In the course of the glycine experiments, we developed a reliable gas chromatographic method to quantify the cyclic dipeptide 2,5-diketopiperazine. The decomposition of linoleic acid in wet‒dry cycles was promoted by both air and olivine. And finally, the extremely oxygen-sensitive pyrogallol solution was used as a colour indicator for residual oxygen in the WDA. The simulation facility in our laboratory currently consists of eight identical WDAs and a surrounding infrastructure. It can be made available to others who wish to perform cyclic wet–dry experiments.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Saturn's moon Enceladus has vents emerging from a sub-surface ocean, offering unique probes into the liquid environment. These vents drain into the larger neutral torus in orbit around Saturn. We present a methanol (CH〈span〉3〈/span〉OH) detection observed with IRAM 30-m from 2008 along the line-of-sight through Saturn's E-ring. Additionally, we also present supporting observations from the 〈span〉Herschel〈/span〉 public archive of water (ortho-H〈span〉2〈/span〉O; 1669.9 GHz) from 2012 at a similar elongation and line-of-sight. The CH〈span〉3〈/span〉OH 5(1,1)-4(1,1) transition was detected at 5.9〈span〉σ〈/span〉 confidence. The line has 0.43 km s〈span〉−1〈/span〉 width and is offset by +8.1 km s〈span〉−1〈/span〉 in the moon's reference frame. Radiative transfer models allow for gas cloud dimensions from 1750 km up to the telescope beam diameter ~73 000 km. Taking into account the CH〈span〉3〈/span〉OH lifetime against solar photodissociation and the redshifted line velocity, there are two possible explanations for the CH〈span〉3〈/span〉OH emission: methanol is primarily a secondary product of chemical interactions within the neutral torus that: (1) spreads outward throughout the E-ring or (2) originates from a compact, confined gas cloud lagging Enceladus by several km s〈span〉−1〈/span〉. We find either scenario to be consistent with significant redshifted H〈span〉2〈/span〉O emission (4〈span〉σ〈/span〉) measured from the 〈span〉Herschel〈/span〉 public archive. The measured CH〈span〉3〈/span〉OH:H〈span〉2〈/span〉O abundance (〉0.5%) significantly exceeds the observed abundance in the direct vicinity of the vents (~0.01%), suggesting CH〈span〉3〈/span〉OH is likely chemically processed within the gas cloud with methane (CH〈span〉4〈/span〉) as its parent species.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Making predictions about aliens is not an easy task. Most previous work has focused on extrapolating from empirical observations and mechanistic understanding of physics, chemistry and biology. Another approach is to utilize theory to make predictions that are not tied to details of Earth. Here we show how evolutionary theory can be used to make predictions about aliens. We argue that aliens will undergo natural selection – something that should not be taken for granted but that rests on firm theoretical grounds. Given aliens undergo natural selection we can say something about their evolution. In particular, we can say something about how complexity will arise in space. Complexity has increased on the Earth as a result of a handful of events, known as the major transitions in individuality. Major transitions occur when groups of individuals come together to form a new higher level of the individual, such as when single-celled organisms evolved into multicellular organisms. Both theory and empirical data suggest that extreme conditions are required for major transitions to occur. We suggest that major transitions are likely to be the route to complexity on other planets, and that we should expect them to have been favoured by similarly restrictive conditions. Thus, we can make specific predictions about the biological makeup of complex aliens.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉 〈p〉This paper is profoundly innovative for the Evo-SETI (Evolution and SETI) mathematical theory. While this author's previous papers were all based on the notion of a b-lognormal, that is a probability density function in the time describing one's life between birth and ‘senility’ (the descending inflexion point), in this paper the b-lognormals range between birth and peak only, while a descending parabola covers the lifespan after the peak and down to death. The resulting finite curve in time is called a LOGPAR, a nickname for ‘b-LOGnormal and PARabola’. The advantage of such a formulation is that three variables only (birth, peak and death) are sufficient to describe the whole Evo-SETI theory and the senility is discarded forever and so is the normalization condition of b-lognormals: only the shape of the b-lognormals is kept between birth and peak, but not its normalization condition.〈/p〉 〈p〉In addition, further advantages exist:〈/p〉 〈p〉1) The notion of ENERGY becomes part of Evo-SETI theory. This is in addition to the notion of ENTROPY already contained in the theory as the Shannon Information Entropy of b-lognormals, as it was explored in this author's previous papers. Actually, the LOGPAR may now be regarded as a POWER CURVE, i.e. a curve expressing the power of the living being to which it refers. And this power is to be understood both in the strict sense of physics (i.e. a curve measured in Watts) and in the loose sense of ‘political power’ if the logpar refers to a Civilization.〈/p〉 〈p〉Then the integral in the time of this power curve is, of course, the ENERGY either absorbed or produced by the physical phenomenon that the LOGPAR is describing in the time. For instance, if the logpar shows the time evolution of the Sun over about 10 billion years, the integral of such a curve is the energy produced by the Sun over the whole of its lifetime. Or, if the logpar describes the life of a man, the integral is the energy that this man must use in order to live.〈/p〉 〈p〉2) The PRINCIPLE OF LEAST ENERGY, reminiscent of the Principle of Least Action, i.e. the key stone to all Physics, also enters now into the Evo-SETI Theory by virtue of the so-called LOGPAR HISTORY FORMULAE, expressing the b-lognormal's mu and sigma directly in terms of the three only inputs 〈span〉b〈/span〉, 〈span〉p〈/span〉, 〈span〉d〈/span〉. The optimization of the lifetime of a living creature, or of a Civilization, or of a star, is obtained by setting to zero the first derivative of the area under the logpar power curve with respect to sigma. That yields the best value of both mu and sigma fulfilling the Principle of Least Energy for Evo-SETI Theory.〈/p〉 〈p〉3) We also derive for the first time a few more mathematical equations related to the ‘adolescence’ (or ‘puberty’) time, i.e. the time when the living organism acquires the capability of producing offsprings. This time is defined as the abscissa of ascending inflection point of the b-lognormal between birth and peak. In addition, we prove that the straight line parallel to the time axis and departing from the puberty time comes to mean the ‘Fertility Span’ in between puberty and the EOF (End-Of-Fertility time), which is where the above straight line intersects the descending parabola. All these new results apply well to the description of Man as the living creature to which our Evo-SETI mathematical theory perfectly applies.〈/p〉 〈p〉In conclusion, this paper really breaks new mathematical ground in Evo-SETI Theory, thus paving the way to further applications of the theory to Astrobiology and SETI.〈/p〉 〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉We undertook observations with the Green Bank Telescope, simultaneously with the 300 m telescope in Arecibo, as a follow-up of a possible flare of radio emission from Ross 128. We report here the non-detections from the GBT observations in C band (4–8 GHz), as well as non-detections in archival data at L band (1.1–1.9 GHz). We suggest that a likely scenario is that the emission comes from one or more satellites passing through the same region of the sky.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Recent paper by Robert Klee in this journal argues that we should endorse a form of cosmic pessimism due to the inevitable destruction of Earth and humanity, allegedly meaning the complete and total annihilation of all traces of humanity's existence (‘human expunction’). It could be shown that both the physical basis and philosophical methodology used by Klee to reach those bleak conclusions are at best premature and at worst unwarranted and misleading. Even worse, they reflect a mindset of unjustified and narrow-minded technological and societal pessimism, which contributes to the erosion of the Enlightenment values, the loss of public interest in space research and colonization, and could indeed increase vulnerability to real – as opposed to uncertain eschatological – global risks humanity is facing in this millennium.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉One of the future challenges to produce food in a Mars environment will be the optimization of resources through the potential use of the Martian substratum for growing crops as a part of bioregenerative food systems. 〈span〉In vitro〈/span〉 plantlets from 65 potato genotypes were rooted in peat-pellets substratum and transplanted in pots filled with Mars-like soil from La Joya desert in Southern Peru. The Mars-like soil was characterized by extreme salinity (an electric conductivity of 19.3 and 52.6 dS m〈span〉−1〈/span〉 under 1 : 1 and saturation extract of the soil solution, respectively) and plants grown in it were under sub-optimum physiological status indicated by average maximum stomatal conductance 2O m〈span〉−2〈/span〉 s〈span〉−1〈/span〉 even after irrigation. 40% of the genotypes survived and yielded (0.3–5.2 g tuber plant〈span〉−1〈/span〉) where CIP.397099.4, CIP.396311.1 and CIP.390478.9 were targeted as promising materials with 9.3, 8.9 and 5.8% of fresh tuber yield in relation to the control conditions. A combination of appropriate genotypes and soil management will be crucial to withstand extreme salinity, a problem also important in agriculture on Earth that requires more detailed follow-up studies.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Recent technological advances could make interstellar travel possible, using ultra-lightweight sails pushed by lasers or solar photon pressure, at speeds of a few per cent the speed of light. Obtaining remote observational data from such probes is not trivial because of their minimal instrumentation (gram scale) and large distances (pc). We derive the optimal communication scheme to maximize the data rate between a remote probe and home-base. The framework requires coronagraphic suppression of the stellar background at the level of 10〈span〉−9〈/span〉 within a few tenths of an arcsecond of the bright star. Our work includes models for the loss of photons from diffraction, technological limitations, interstellar extinction and atmospheric transmission. Major noise sources are atmospheric, zodiacal, stellar and instrumental. We examine the maximum capacity using the ‘Holevo bound’ which gives an upper limit to the amount of information (bits) that can be encoded through a quantum state (photons), which is a few bits per photon for optimistic signal and noise levels. This allows for data rates of the order of bits per second per Watt from a transmitter of size 1 m at a distance of 〈span〉α〈/span〉 Centauri (1.3 pc) to an earth-based large receiving telescope (E-ELT, 39 m). The optimal wavelength for this distance is 300 nm (space-based receiver) to 400 nm (earth-based) and increases with distance, due to extinction, to a maximum of ≈ 3 〈span〉μ〈/span〉m to the centre of the Galaxy at 8 kpc.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Pulsars have at least two impressive applications. First, they can be used as highly accurate clocks, comparable in stability to atomic clocks; secondly, a small subset of pulsars, millisecond X-ray pulsars, provide all the necessary ingredients for a passive galactic positioning system. This is known in astronautics as X-ray pulsar-based navigation (XNAV). XNAV is comparable to GPS, except that it operates on a galactic scale. I propose a SETI-XNAV research program to test the hypothesis that this pulsar positioning system might be an instance of galactic-scale engineering by extraterrestrial beings. The paper starts by exposing the basics of pulsar navigation, continues with a critique of the rejection of the extraterrestrial hypothesis when pulsars were first discovered. The core section of the paper proposes lines of inquiry for SETI-XNAV, related to the pulsar distribution and power in the galaxy; their population; their evolution; possible pulse synchronizations; pulsar usability when navigating near the speed of light; decoding galactic coordinates; directed panspermia; and information content in pulses. Even if pulsars are natural, they are likely to be used as standards by ETIs in the galaxy. I discuss possible objections and potential benefits for humanity, whether the research program succeeds or not.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉A planet may be defined as habitable if it has an atmosphere and is warm enough to support the existence of liquid water on its surface. Such a world has the basic set of conditions that allow it to develop life similar to ours, which is carbon-based and has water as its universal solvent. While this definition is suitably vague to allow a fairly broad range of possibilities, it does not address the question as to whether any life that does form will become either complex or intelligent. In this paper, we seek to synthesize a qualitative definition of which subset of these ‘habitable worlds’ might develop more complex and interesting life forms. We identify two key principles in determining the capacity of life to breach certain transitions on route to developing intelligence. The first is the number of potential niches a planet provides. Secondly, the complexity of life will reflect the information density of its environment, which in turn can be approximated by the number of available niches. We seek to use these criteria to begin the process of placing the evolution of terrestrial life in a mathematical framework based on environmental information content. This is currently testable on Earth and will have clear application to the worlds that we are only beginning to discover. Our model links the development of complex life to the physical properties of the planet, something which is currently lacking in all evolutionary theory.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The aim of this study is to increase our understanding of the attitudes towards the scientific search for extraterrestrial life among high school and university students in Sweden. The most important results of the analysis are that: (a) the great majority of students believe that extraterrestrial life exists; (b) most students regard searching for extraterrestrial life to be quite important or very important; (c) very few students think that we should actively avoid searching for extraterrestrial life; (d) the most common motive for assigning a high priority to search for extraterrestrial life is that it is interesting, the most common motive for assigning a low priority is that such knowledge would not be practically useful, or that the money would be better spent elsewhere; (e) most students do not think they are very well informed regarding the search for extraterrestrial life. A higher percentage of the students who judge themselves to be well informed also believe that extraterrestrial life exists. We have also found some differences between subgroups (men/women, high school students/university students and different fields of study), but the differences are with few exceptions small in comparison with the overall trends, and they mostly differ in degree rather than direction.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Massive to lobate volcanic flows and brecciated hyaloclastite units in the Abitibi greenstone belt allow investigation of Late Archæan seafloor alteration and associated incorporation into these rocks of nitrogen (N) biogeochemical signatures. In this suite (the Blake River Group), hyaloclastite units containing putative microbial ichnofossils are particularly enriched in large-ion lithophile elements (K, Rb, Ba, Cs), B, and Li, consistent with their having experienced the greatest fluid–rock interaction during subseafloor hydrothermal alteration. Similarly, silicate-δ〈span〉18〈/span〉O and δ〈span〉15〈/span〉N values for samples from the hyaloclastites show the greatest shifts from plausible magmatic values. The chemical and isotopic patterns in these tholeiitic igneous rocks greatly resemble those in modern altered seafloor basalts, consistent with the preservation of an Archæan seafloor alteration signature. The N enrichments and shifts in δ〈span〉15〈/span〉N appear to reflect stabilization of illite and interaction with fluids carrying sedimentary/organic signatures. Enrichments of N (and the δ〈span〉15〈/span〉N of this N) in altered glass volcanic rocks on Earth's modern and ancient seafloor point to the potential utility of N for tracing past and present biogeochemical processes in similar rocks at/near the Mars surface.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The 21 cm hydrogen line is considered a favourable frequency by the SETI programme in their search for signals from potential extraterrestrial (ET) civilizations. The Pioneer plaque, attached to the Pioneer 10 and Pioneer 11 spacecraft, portrays the hyperfine transition of neutral hydrogen and used the wavelength as a standard scale of measurement. Although this line would be universally recognized and is a suitable wavelength to look for radio signals from ETs, the presence of ubiquitous radiation from galactic hydrogen could make searches a little difficult. In this paper, we suggest several alternate standard frequencies, which are free of interference from atomic or molecular sources and is independent of any bias.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Punctuated equilibrium, in the sense of Eldredge and Gould in 1972, and path dependence (Gould in 2002), dominate evolutionary processes, many of whose dynamics can be expressed in terms of interacting information sources (Wallace in 2010). Argument based on Feynman's (in 2000) characterization of information as a form of free energy leads to a close, if inverse, analogy between evolutionary transitions and economic ratchets. Driven by such a ‘self-referential’ mechanism, increases in available metabolic free energy – via the aerobic transition – led to the eukaryotic transition and to life as we know it. Formal analysis focuses on groupoid symmetries associated with the cognitive processes of gene expression, an extension of the symmetry breaking/making perspectives of physical science into biological phenomena. This suggests that understanding modalities of cognitive gene expression, as opposed to focus on genes themselves, provides the deepest insight into evolutionary phenomena, a perspective at some variance with current simplistic gene-centred views that constrain evolutionary theory.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉We draw attention to a curious coincidence wherein the most (steadily emitting) luminous objects in the Universe from stellar X-ray sources to ultra-luminous quasars and Ultra Luminous Infrared Galaxies, steadily emit a power per unit mass, which is just the same value as the maximal metabolic rate in (warm-blooded) bio-organisms.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉Two fundamental problems for extraterrestrial intelligences (ETIs) attempting to establish interstellar communication are timing and energy consumption. Humanity's study of exoplanets via their transit across the host star highlights a means of solving both problems. An ETI ‘A’ can communicate with ETI ‘B’ if B is observing transiting planets in A's star system, either by building structures to produce artificial transits observable by B, or by emitting signals at B during transit, at significantly lower energy consumption than typical electromagnetic transmission schemes. This can produce a network of interconnected civilizations, establishing contact via observing each other's transits. Assuming that civilizations reside in a Galactic Habitable Zone (GHZ), I conduct Monte Carlo Realization simulations of the establishment and growth of this network, and analyse its properties in the context of graph theory. I find that at any instant, only a few civilizations are correctly aligned to communicate via transits. However, we should expect the true network to be cumulative, where a ‘handshake’ connection at any time guarantees connection in the future via e.g. electromagnetic signals. In all our simulations, the cumulative network connects all civilizations together in a complete network. If civilizations share knowledge of their network connections, the network can be fully complete on timescales of order a hundred thousand years. Once established, this network can connect any two civilizations either directly, or via intermediate civilizations, with a path much less than the dimensions of the GHZ.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The paper proposes a scenario of origin and emerging of intelligent life in Universe based upon the mathematical discovery of a new class of dynamical systems described by ordinary differential equation (ODE) coupled with their Liouville equation. These systems called self-controlled since the role of actuators is played by the probability produced by the Liouville equation. Following the Madelung equation that belongs to this class, non-Newtonian and quantum-like properties such as randomness, entanglement and probability interference typical for quantum systems have been described. At the same time, these systems expose properties of 〈span〉livings〈/span〉: decomposition into motor and mental dynamics, the capability of self-identification and self-awareness, as well as self-supervision. But the most surprising discovery is the existence of a special sub-class, in which the dynamical systems can violate the second law of thermodynamics, and that makes them different from both Newtonian and quantum physics. This sub-class should be associated with 〈span〉intelligent livings〈/span〉 due to capability to move from disorder to order without external help. Based upon the 〈span〉mathematical〈/span〉 discovery described above, one can assume that there are good chances that similar dynamical systems representing 〈span〉intelligent livings〈/span〉 exist in real physical world. This provides a reason for a ‘rehabilitation’ of the Maxwell demon and put it into physics of 〈span〉intelligent system〈/span〉s. Indeed, the Maxwell demon is implemented by the feedback from the Liouville equation to the original ODE, while this feedback is capable to rearrange the probability distribution against the second law of thermodynamics. In addition to that, the same feedback removes the entropy paradox by explaining high order in our surrounding by ‘intelligent life support’. Two-steps transition: from the Newtonian physics to the linear model of life, and from the latter to the model of intelligent life are analysed. The first transition is triggered by the Hadamard instability of the Newtonian physics with respect to small random disturbances in linear terms of the Liouville feedback. The second transition is triggered by instability of linear model of life with respect to small random disturbances of non-linear terms of Liouville feedback. This transition could be implemented by such physical phenomena as shock waves or negative diffusion in probability space. Both transitions can be associated with catastrophe theory, in which sudden shifts in behaviour arises from small changes in parameters of the model. In view of the proposed model, possible competition between artificial and human intelligence are discussed.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉The concept of sustainability is widely acknowledged as a political guideline. Economic, ecological, social and cultural aspects of sustainability are already under discussion. Current space mining efforts demand that the discussion become a broader one about ‘planetary sustainability’, including the space surrounding Earth. To date, planetary sustainability has mainly been used with reference to Earth only and I will extend it here, elaborating on a similar NASA initiative. This article (1) sketches the contemporary economic–political initiatives which call for a special reflection of Earth's location in space, and then (2) discusses the meaning of the concept of sustainability in this context. Next, (3) I relate the discussion to the issue of planetary and environmental protection, before, (4) finally, presenting a philosophical and theological perspective that seems particularly able to broach the issue of the multiple dimensions of sustainability in this context. This is the concept of constructive-critical realism. My overview of the topic concludes with (5) a summarizing outlook.〈/p〉〈/div〉

Description: 〈div data-abstract-type="normal"〉〈p〉We study the prospects for life on planets with subsurface oceans, and find that a wide range of planets can exist in diverse habitats with ice envelopes of moderate thickness. We quantify the energy sources available to these worlds, the rate of production of prebiotic compounds, and assess their potential for hosting biospheres. Life on these planets is likely to face challenges, which could be overcome through a combination of different mechanisms. We estimate the number of such worlds, and find that they may outnumber rocky planets in the habitable zone of stars by a few orders of magnitude.〈/p〉〈/div〉

Description: Research Articles Janelle R. Laing, Hailey C. Robichaud, Edward A. Cloutis, International Journal of Astrobiology , Volume 15 Issue 02 , pp 119-126 Abstract

Description: Research Articles M. Safonova, J. Murthy, Yu. A. Shchekinov, International Journal of Astrobiology , Volume 15 Issue 02 , pp 93-105 Abstract

Description: Research Articles Z. Osmanov, International Journal of Astrobiology , Volume 15 Issue 02 , pp 127-132 Abstract

Description: Research Articles O. V. Mukbaniani, J. N. Aneli, E. G. Markarashvili, M. V. Tarasashvili, N. D. Aleksidze, International Journal of Astrobiology , Volume 15 Issue 02 , pp 155-160 Abstract

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Description: Research Articles Jochen Jänchen, Nina Feyh, Ulrich Szewzyk, Jean-Pierre P. de Vera, International Journal of Astrobiology , Volume 15 Issue 02 , pp 107-118 Abstract

Description: Research Articles Anna Neubeck, Marek Tulej, Magnus Ivarsson, Curt Broman, Andreas Riedo, Sean McMahon, Peter Wurz, Stefan Bengtson, International Journal of Astrobiology , Volume 15 Issue 02 , pp 133-146 Abstract

Description: Research Articles Michael Gilichinsky, Nikita Demidov, Elizaveta Rivkina, International Journal of Astrobiology , Volume 14 Issue 04 , pp 537-545 Abstract

Description: Research Articles Christoph Bergmann, Michael Endl, John B. Hearnshaw, Robert A. Wittenmyer, Duncan J. Wright, International Journal of Astrobiology , Volume 14 Special Issue 02 , pp 173-176 Abstract

Description: Research Articles R. C. Domingos, O. C. Winter, A. Izidoro, International Journal of Astrobiology , Volume 14 Special Issue 02 , pp 153-163 Abstract

Description: Research Articles Elke Pilat-Lohinger, International Journal of Astrobiology , Volume 14 Special Issue 02 , pp 145-152 Abstract

Description: Research Articles Lena Noack, Cyprien Verseux, Paloma Serrano, Michaela Musilova, Philippe Nauny, Toby Samuels, Petra Schwendner, Eugenio Simoncini, Adam Stevens, International Journal of Astrobiology , Volume 14 Issue 04 , pp 533-535 Abstract

Description: Review Articles Sean McMahon, Charles Cockell, International Journal of Astrobiology , Volume 14 Issue 04 , pp 527-531 Abstract

Description: Research Articles Françoise Pauzat, Gael Marloie, Alexis Markovits, Yves Ellinger, International Journal of Astrobiology , Volume 14 Issue 04 , pp 563-570 Abstract

Description: Research Articles Daniel Cartin, International Journal of Astrobiology , Volume 14 Issue 04 , pp 571-575 Abstract

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