5,486 results on '"Exobiology"'
Search Results
102. Eight Metagenome-Assembled Genomes Provide Evidence for Microbial Adaptation in 20,000- to 1,000,000-Year-Old Siberian Permafrost.
- Author
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Sipes, Katie, Almatari, Abraham, Eddie, Alexander, Williams, Daniel, Spirina, Elena, Rivkina, Elizaveta, Renxing Liang, Onstott, Tullis C., Vishnivetskaya, Tatiana A., and Lloyd, Karen G.
- Subjects
- *
PERMAFROST , *TREHALOSE , *COLD adaptation , *GENOMES , *CARBOHYDRATE metabolism , *EXTREME environments , *ENERGY conversion , *THYMINE - Abstract
Permafrost microbes may be metabolically active in microscopic layers of liquid brines, even in ancient soil. Metagenomics can help discern whether permafrost microbes show adaptations to this environment. Thirty-three metagenome-assembled genomes (MAGs) were obtained from six depths (3.5 m to 20 m) of freshly cored permafrost from the Siberian Kolyma-Indigirka Lowland region. These soils have been continuously frozen for; 20,000 to 1,000,000 years. Eight of these MAGs were $80% complete with ,10% contamination and were taxonomically identified as Aminicenantes, Atribacteria, Chloroflexi, and Actinobacteria within bacteria and Thermoprofundales within archaea. MAGs from these taxa have been obtained previously from nonpermafrost environments and have been suggested to show adaptations to long-term energy starvation, but they have never been explored in ancient permafrost. The permafrost MAGs had greater proportions in the Clusters of Orthologous Groups (COGs) categories of energy production and conversion and carbohydrate transport and metabolism than did their nonpermafrost counterparts. They also contained genes for trehalose synthesis, thymine metabolism, mevalonate biosynthesis, and cellulose degradation, which were less prevalent in nonpermafrost genomes. Many of these genes are involved in membrane stabilization and osmotic stress responses, consistent with adaptation to the anoxic, high-ionic-strength, cold environments of permafrost brine films. Our results suggest that this ancient permafrost contains DNA of high enough quality to assemble MAGs from microorganisms with adaptations to survive long-term freezing in this extreme environment. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
103. Heavenly Bodies: Scientific racism and the taxonomy of extraterrestrial life.
- Author
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HAUMAN, NICHOLAS
- Subjects
SCIENTIFIC racism ,EXTRATERRESTRIAL life ,POSTCOLONIALISM ,RACIALIZATION ,MOON - Abstract
In recent years postcolonialism has shifted from exploring the occidental construction of the orient to exploring the role of the occident's colonial other, the orient, in these constructions through the act of hybridity; that is, the influence that real colonial others have on Orientalizing discourse. But what if the literal existence of the other being analyzed cannot be substantiated. Through an analysis of various scientific constructions of extraterrestrials, such as the inhabitants of the moon described by Johannes Kepler or the description of faraway alien races by Ronald Bracewell, this essay examines how the methods of otherizing practiced on creatural populations whose existence is believed but unsubstantiated, others for whom hybridity is impossible, are then applied to real colonial subjects. Mirroring the role of the medieval Plinian races of India and Africa in providing a mythical structure for the construction of race during early capitalist expansion in South America, modern extraterrestrials have provided a mythical structure for the construction and maintenance of racialized others. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
104. Gaze-scaling: Planets as Islands in Exobiologists' Imaginaries.
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Webb, Claire Isabel
- Subjects
- *
SPACE Age, 1957- , *PLANETS , *ISLANDS , *ASTROBIOLOGY , *SOLAR system , *EXTRATERRESTRIAL beings , *PLANETARY science - Abstract
From the late 1950s to the early 1970s, scientists and engineers in the U.S. chartered a new field, exobiology: the search for organic life beyond Earth. Joshua Lederberg, a Nobel Prize-winning scientist, led exobiologists in framing a powerful sociotechnical imaginary for the emergent discipline, one that envisioned planets as islands. That vision followed long traditions in natural science, literature, and geography in which islands had been posited along dueling edges: fragile, bounded sites that required preservation, but ones that also been staged as bountiful, inviting exploration, even exploitation. From Lederberg's archive, other historical sources, and astronautical accounts of seeing Earth from above in the Space Age, the conceptual duality of islands – as enclosed and expansive – transferred to how exobiologists considered their solar system. Planets, including Earth, came to be imagined as biospheres to be preserved, but simultaneously as sites that could possibly underwrite humans' future colonization. Such speculation was supported by a rich visual culture of technologically animated perception, from Apollo 8's Earthrise photograph (1968) to Mariner 9's (1970) televisual images. Scaling the gaze of planetary science from Earth to extraterrestrial sites, exobiologists' planets-as-islands imaginary forecasted a cosmic archipelago of interconnected life in the post-World War II era. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
105. Preserved Filamentous Microbial Biosignatures in the Brick Flat Gossan, Iron Mountain, California
- Author
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Williams, Amy J, Sumner, Dawn Y, Alpers, Charles N, Karunatillake, Suniti, and Hofmann, Beda A
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Astronomical Sciences ,Physical Sciences ,California ,Exobiology ,Extraterrestrial Environment ,Ferric Compounds ,Fossils ,Geologic Sediments ,Iron ,Iron Compounds ,Mars ,Microbiological Phenomena ,Microscopy ,Electron ,Scanning ,Mineral Fibers ,Minerals ,Quartz ,Sulfides ,Astronomical and Space Sciences ,Geochemistry ,Geology ,Astronomy & Astrophysics ,Astronomical sciences - Abstract
A variety of actively precipitating mineral environments preserve morphological evidence of microbial biosignatures. One such environment with preserved microbial biosignatures is the oxidized portion of a massive sulfide deposit, or gossan, such as that at Iron Mountain, California. This gossan may serve as a mineralogical analogue to some ancient martian environments due to the presence of oxidized iron and sulfate species, and minerals that only form in acidic aqueous conditions, in both environments. Evaluating the potential biogenicity of cryptic textures in such martian gossans requires an understanding of how microbial textures form biosignatures on Earth. The iron-oxide-dominated composition and morphology of terrestrial, nonbranching filamentous microbial biosignatures may be distinctive of the underlying formation and preservation processes. The Iron Mountain gossan consists primarily of ferric oxide (hematite), hydrous ferric oxide (HFO, predominantly goethite), and jarosite group minerals, categorized into in situ gossan, and remobilized iron deposits. We interpret HFO filaments, found in both gossan types, as HFO-mineralized microbial filaments based in part on (1) the presence of preserved central filament lumina in smooth HFO mineral filaments that are likely molds of microbial filaments, (2) mineral filament formation in actively precipitating iron-oxide environments, (3) high degrees of mineral filament bending consistent with a flexible microbial filament template, and (4) the presence of bare microbial filaments on gossan rocks. Individual HFO filaments are below the resolution of the Mars Curiosity and Mars 2020 rover cameras, but sinuous filaments forming macroscopic matlike textures are resolvable. If present on Mars, available cameras may resolve these features identified as similar to terrestrial HFO filaments and allow subsequent evaluation for their biogenicity by synthesizing geochemical, mineralogical, and morphological analyses. Sinuous biogenic filaments could be preserved on Mars in an iron-rich environment analogous to Iron Mountain, with the Pahrump Hills region and Hematite Ridge in Gale Crater as tentative possibilities.
- Published
- 2015
106. Nonphotosynthetic Pigments as Potential Biosignatures
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Schwieterman, Edward W, Cockell, Charles S, and Meadows, Victoria S
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Astronomical Sciences ,Physical Sciences ,Bacteria ,Color ,Exobiology ,Forests ,Models ,Theoretical ,Oceans and Seas ,Photosynthesis ,Pigments ,Biological ,Planets ,Spectrum Analysis ,Astronomical and Space Sciences ,Geochemistry ,Geology ,Astronomy & Astrophysics ,Astronomical sciences - Abstract
Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data.
- Published
- 2015
107. Live Long and Evolve : What Star Trek Can Teach Us About Evolution, Genetics, and Life on Other Worlds
- Author
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Mohamed A. F. Noor and Mohamed A. F. Noor
- Subjects
- Exobiology, Genetics, Star Trek television programs, Evolution
- Abstract
An engaging journey into the biological principles underpinning a beloved science-fiction franchiseIn Star Trek, crew members travel to unusual planets, meet diverse beings, and encounter unique civilizations. Throughout these remarkable space adventures, does Star Trek reflect biology and evolution as we know it? What can the science in the science fiction of Star Trek teach us? In Live Long and Evolve, biologist and die-hard Trekkie Mohamed Noor takes readers on a fun, fact-filled scientific journey.Noor offers Trekkies, science-fiction fans, and anyone curious about how life works a cosmic gateway into introductory biology, including the definitions and origins of life, DNA, reproduction, and evolutionary processes, such as natural selection and genetic drift. For instance, he shows how the rapid change in a population of nanite robots follows basic principles of natural selection that apply to species on Earth. He explains how certain creatures depicted in the series are bisexual, not asexual, and what evolutionary advantage that difference provides. And he considers factors that affect successful interspecies mating and delves into what keeps species distinct. Noor discusses the importance of research and how Star Trek has influenced scientists to engage in cutting-edge work.Giving readers irresistible and entertaining insights, Live Long and Evolve looks at some of the powerful science behind one of the most popular and longest-running science-fiction series.
- Published
- 2018
108. Habitability of the Universe Before Earth : Astrobiology: Exploring Life on Earth and Beyond (series)
- Author
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Richard Gordon, Alexei Sharov, Richard Gordon, and Alexei Sharov
- Subjects
- Exobiology, Habitable planets
- Abstract
Habitability of the Universe before Earth: Astrobiology: Exploring Life on Earth and Beyond (series) examines the times and places—before life existed on Earth—that might have provided suitable environments for life to occur, addressing the question: Is life on Earth de novo, or derived from previous life? The universe changed considerably during the vast epoch between the Big Bang 13.8 billion years ago and the first evidence of life on Earth 4.3 billion years ago, providing significant time and space to contemplate where, when and under what circumstances life might have arisen. No other book covers this cosmic time period from the point of view of its potential for life. The series covers a broad range of topics encompassing laboratory and field research into the origins and evolution of life on Earth, life in extreme environments and the search for habitable environments in our solar system and beyond, including exoplanets, exomoons and astronomical biosignatures. - Provides multiple hypotheses on the origin of life and distribution of living organisms in space - Explores the diversity of physical environments that may support the origin and evolution of life - Integrates contemporary views in biology and cosmology, and provides reasons that life is far more mobile in space than most people expect - Includes access to a companion web site featuring supplementary information such as animated computer simulations
- Published
- 2018
109. The Equations of Life : How Physics Shapes Evolution
- Author
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Charles Cockell and Charles Cockell
- Subjects
- Exobiology, Evolution (Biology)--Philosophy, Physics--Philosophy
- Abstract
One of Britain's foremost astrobiologists offers an accessible and game-changing account of life on Earth. __________________ Why is all life based on carbon rather than silicon? And beyond Earth, would life - if it exists - look like our own? __________________ The puzzles of life astound and confuse us like no other mystery. But in this groundbreaking book, Professor Charles Cockell reveals how nature is far more understandable and predictable than we would think. Breathing new life into Darwin's theory of natural selection, The Equations of Life puts forward an elegant account of why evolution has taken the paths it has. In a captivating journey into the forces that shape living things on Earth, Cockell explains that the fundamental laws of physics constrain nature at every turn. Fusing the latest in scientific research with fascinating accounts of the creatures that surround us, this is a compelling argument about what life can - and can't - be.
- Published
- 2018
110. Universal Life : An Inside Look Behind the Race to Discover Life Beyond Earth
- Author
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Alan Boss and Alan Boss
- Subjects
- Habitable planets, Exobiology
- Abstract
After decades of painstaking planning, NASA's first dedicated exoplanet detection mission, the Kepler space telescope, was launched in 2009 from Cape Canaveral. Kepler began a years-long mission of looking for Earth-like planets amongst the millions of stars in the northern constellations of Lyra and Cygnus. Kepler's successful launch meant that it was only a matter of time before we would know just how many Earth-like planets exist in our galaxy. A revolution in thinking about our place in the universe was about to occur, depending on what Kepler found. Are earths commonplace or rare? Are we likely to be alone in the universe? Only Kepler could start to answer these vexing questions. Universal Life provides a unique viewpoint on the epochal events of the last two decades and the excitement of what will transpire in the coming decades. Author Alan Boss's perspective on this story is unmatched. Boss is the Chair of NASA's Exoplanet Exploration Program Analysis Group, and was also on the Kepler Mission science team. Kepler proved that essentially every star in the night sky has a planetary system, and that most of these systems contain a habitable world, potentially capable of evolving and supporting life. Universal Life summarizes the current state of exoEarth knowledge, and also reveals what will happen next in the post-Kepler world, namely the narrowing of the search for habitable worlds to the stars that are the closest to Earth, those that offer the best chances for future ground- and space-based telescopes to search for, and detect, possible signs of life in their atmospheres. We have come far in the search for life beyond the Earth, but the most exciting phase is about to begin: we may soon be able to prove that we are not alone in the universe.
- Published
- 2018
111. Current Trends in Astrobiology
- Author
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Kenath Arun, Author, C Sivaram, Author, Kiren O V, Author, Kenath Arun, Author, C Sivaram, Author, and Kiren O V, Author
- Subjects
- Life on other planets, Astronautics, Exobiology, Extrasolar planets, Life--Origin
- Abstract
Astrobiology is a rapidly emerging field of intense scientific and technological activity, evident from the numerous recent space probes attempting to look for the possible existence of alien primeval life. This book explores the possibility of life on other planets and moons and exoplanets, either in their parent stars'habitable zones or as free-floating exoplanets. The wide range of topics discussed here include environments influencing the origin and evolution of life and cosmological effects, such as the implications of a dark energy-dominated universe for astrobiology. Astrobiology is a highly interdisciplinary subject involving astronomy, physics, biology, geology, and chemistry, in addition to being a technology-intensive discipline. This book highlights the various methods used to detect possible advanced alien technology combining all these areas.
- Published
- 2018
112. Universal Biology After Aristotle, Kant, and Hegel : The Philosopher's Guide to Life in the Universe
- Author
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Richard Dien Winfield and Richard Dien Winfield
- Subjects
- Life on other planets, Life (Biology), Life, Exobiology
- Abstract
Here is a universal biology that draws upon the contributions of Aristotle, Kant, and Hegel to unravel the mystery of life and conceive what is essential to living things anywhere they may arise. The book develops a philosopher's guide to life in the universe, conceiving how nature becomes a biosphere in which life can emerge, what are the basic life processes common to any organism, how evolution can give rise to the different possible forms of life, and what distinguishes the essential life forms from one another.
- Published
- 2018
113. Astrobiology and Society in Europe Today
- Author
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Klara Anna Capova, Erik Persson, Tony Milligan, David Dunér, Klara Anna Capova, Erik Persson, Tony Milligan, and David Dunér
- Subjects
- Life--Origin, Exobiology--Social aspects, Exobiology, Exobiology--Research--Europe
- Abstract
This White Paper describes the state of astrobiology in Europe today and its relation to the European society at large. With contributions from authors in twenty countries and over thirty scientific institutions worldwide, the document illustrates the societal implications of astrobiology and the positive contribution that astrobiology can make to European society. The White paper has two main objectives: 1. It recommends the establishment of a European Astrobiology Institute (EAI) as an answer to a series of challenges relating to astrobiology but also European research, education and the society at large. 2. It also acknowledges the societal implications of astrobiology, and thus the role of the social sciences and humanities in optimizing the positive contribution that astrobiology can make to the lives of the people of Europe and the challenges they face.This book is recommended reading for science policy makers, the interested public, and the astrobiologycommunity.
- Published
- 2018
114. The Equations of Life : How Physics Shapes Evolution
- Author
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Charles S. Cockell and Charles S. Cockell
- Subjects
- Evolution (Biology)--Philosophy, Physics--Philosophy, Exobiology
- Abstract
A groundbreaking argument for why alien life will evolve to be much like life here on Earth We are all familiar with the popular idea of strange alien life wildly different from life on earth inhabiting other planets. Maybe it's made of silicon! Maybe it has wheels! Or maybe it doesn't. In The Equations of Life, biologist Charles S. Cockell makes the forceful argument that the laws of physics narrowly constrain how life can evolve, making evolution's outcomes predictable. If we were to find on a distant planet something very much like a lady bug eating something like an aphid, we shouldn't be surprised. The forms of life are guided by a limited set of rules, and as a result, there is a narrow set of solutions to the challenges of existence.A remarkable scientific contribution breathing new life into Darwin's theory of evolution, The Equations of Life makes a radical argument about what life can -- and can't -- be.
- Published
- 2018
115. Astrobiology : The Search for Life Elsewhere in the Universe
- Author
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Andrew May and Andrew May
- Subjects
- Exobiology, Life on other planets
- Abstract
Extraterrestrial life is a common theme in science fiction, but is it a serious prospect in the real world? Astrobiology is the emerging field of science that seeks to answer this question. The possibility of life elsewhere in the cosmos is one of the most profound subjects that human beings can ponder. Astrophysicist Andrew May gives an expert overview of our current state of knowledge, looking at how life started on Earth, the tell-tale'signatures'it produces, and how such signatures might be detected elsewhere in the Solar System or on the many'exoplanets'now being discovered by the Kepler and TESS missions. Along the way the book addresses key questions such as the riddle of Fermi's paradox ('Where is everybody?') and the crucial role of DNA and water – they're essential to'life as we know it', but is the same true of alien life? And the really big question: when we eventually find extraterrestrials, will they be friendly or hostile?
- Published
- 2018
116. Space Biology Biospecimen Sharing Program
- Author
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America M Reyes, Christina L Cheung, and Hami E Teal
- Subjects
Exobiology - Published
- 2022
117. Scientific Value of Including an Atmospheric Sample as Part of Mars Sample Return (MSR)
- Author
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Timothy D. Swindle, Sushil Atreya, Henner Busemann, Julia A. Cartwright, Paul Mahaffy, Bernard Marty, Andreas Pack, and Suzanne P. Schwenzer
- Subjects
Lunar And Planetary Science And Exploration ,Exobiology - Abstract
The Perseverance rover is meant to collect samples of the martian surface for eventual return to Earth. The headspace gas present over the solid samples within the sample tubes will be of significant scientific interest for what it reveals about the interactions of the solid samples with the trapped atmosphere and for what it will reveal about the martian atmosphere itself. However, establishing the composition of the martian atmosphere will require other dedicated samples. The headspace gas as the sole atmospheric sample is problematic for many reasons. The quantity of gas present within the sample tube volume is insufficient for many investigations, and there will be exchange between solid samples, headspace gas, and tube walls. Importantly, the sample tube materials and preparation were not designed for optimal Mars atmospheric gas collection and storage as they were not sent to Mars in a degassed evacuated state and have been exposed to both Earth's and Mars' atmospheres. Additionally, there is a risk of unconstrained seal leakage in transit back to Earth, which would allow fractionation of the sample (leak-out) and contamination (leak-in). The science return can be improved significantly (and, in some cases, dramatically) by adding one or more of several strategies listed here in increasing order of effectiveness and difficulty of implementation: (1) Having Perseverance collect a gas sample in an empty sample tube, (2) Collecting gas in a newly-designed, valved, sample-tube-sized vessel that is flown on either the Sample Fetch Rover (SFR) or the Sample Retrieval Lander (SRL), (3) Adding a larger (50-100 cc) dedicated gas sampling volume to the Orbiting Sample container (OS), (4) Adding a larger (50-100 cc) dedicated gas sampling volume to the OS that can be filled with compressed martian atmosphere.
- Published
- 2022
- Full Text
- View/download PDF
118. ThermoBase: A Database of the Phylogeny and Physiology of Thermophilic and Hyperthermophilic Organisms
- Author
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Juliana DiGiacomo, Christopher Mckay, and Alfonso Davila
- Subjects
Exobiology - Abstract
Thermophiles and hyperthermophiles are those organisms which grow at high temperature (> 40°C). The unusual properties of these organisms have received interest in multiple fields of biological research, and have found applications in biotechnology, especially in industrial processes. However, there are few listings of thermophilic and hyperthermophilic organisms and their relevant environmental and physiological data. Such repositories can be used to standardize definitions of thermophile and hyperthermophile limits and tolerances and would mitigate the need for extracting organism data from diverse literature sources across multiple, sometimes loosely related, research fields. Therefore, we have developed ThermoBase, a web-based and freely available database which currently houses comprehensive descriptions for 1238 thermophilic or hyperthermophilic organisms. ThermoBase reports taxonomic, metabolic, environmental, experimental, and physiological information in addition to literature resources. This includes parameters such as coupling ions for chemiosmosis, optimal pH and range, optimal temperature and range, optimal pressure, and optimal salinity. The database interface allows for search features and sorting of parameters. As such, it is the goal of ThermoBase to facilitate and expedite hypothesis generation, literature research, and understanding relating to thermophiles and hyperthermophiles within the scientific community in an accessible and centralized repository. ThermoBase is freely available online at the Astrobiology Habitable Environments Database (AHED; https://ahed.nasa.gov), at the Database Center for Life Science (TogoDB; http://togodb.org/db/thermobase), and in the S1 File.
- Published
- 2022
- Full Text
- View/download PDF
119. Microbial Life in Space
- Author
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RS Thombre, K Kaur, SS Jagtap, J Dixit, and PV Vaishampayan
- Subjects
Exobiology - Abstract
Outer space is a harsh environment harbouring multiple forms of stress like cosmic radiation, space vacuum, extreme temperature and pressure, UV radiations, and altered gravity. Earth’s atmosphere has several layers that expose microbial and terrestrial life to harsh external environments. In order to study the limits of survival of microbial life in extremes, it is imperative to study the response of micro-organisms to space-related stress. The present chapter summarizes the various balloon and flight experiments performed to investigate the presence and response of microbial life in space. Studying the microbiome in the ISS is important as pathogenic bacteria can present a major risk to astronaut health in a closed environment. Hence, studying occurrence, ecology, diversity, response, and adaptations of microbial life in space is crucial to understanding the limits of organismic survival in inhospitable conditions. Studying microbial life in space also helps predict the plausible survival and endurance of microbial travel between planets, crucial to lithopanspermia theories and planetary protection.
- Published
- 2022
120. Life at the end of worlds : modelling the biosignatures of microbial life in diverse environments at the end of the habitable lifetimes of Earth-like planets
- Author
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O'Malley-James, Jack T., Greaves, Jane Sophia, Cockell, Charles, and Raven, John A.
- Subjects
576.8 ,Astrobiology ,Exoplanet ,Biosignature ,Habitability ,QH326.O6 ,Exobiology ,Habitable planets ,Biochemical markers ,Microbiology - Abstract
This thesis investigates how increased global mean temperatures on Earth, induced by the increase in the luminosity of the Sun as it ages, change the types of habitable environments on the planet at local scales over the next 3 Gyr. Rising temperatures enhance silicate weathering rates, reducing atmospheric CO₂ levels to below the threshold for photosynthesis, while simultaneously pushing environments past the temperature tolerances of plant and animal species. This leads to the end of all plant life and animal life (due to reduced food, O₂ and H₂O availability, as well as higher temperatures) within the next 1 Gyr. The reduction in the extent of the remaining microbial biosphere due to increasing temperatures and rapid ocean evaporation is then modelled, incorporating orbital parameter changes until all known types of life become extinct; a maximum of 2.8 Gyr from the present. The biosignatures associated with these changes are determined and the analysis extended to Earth-like extrasolar planets nearing the end of their habitable lifetimes. In particular, the stages in the main sequence evolutions of Sun-like stars within 10 pc are evaluated and used to extrapolate the stage that an Earth-analogue planet would be at in its habitable evolution, to determine the best candidate systems for a far-future Earth-analogue biosphere, highlighting the Beta Canum Venaticorum system as a good target. One of the most promising biosignatures for a microbial biosphere on the far-future Earth (and similar planets) may be CH₄, which could reach levels in the atmosphere that make it more readily detectable than it is for a present-day Earth-like atmosphere. Determining these biosignatures will help expand the search for life to the wider range of environments that will be found as the habitable exoplanet inventory grows and planets are found at different stages in their habitable evolution.
- Published
- 2014
121. Concepts for the Future Exploration of Dwarf Planet Ceres' Habitability
- Author
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Julie Castillo-Rogez, John Brophy, Kelly Miller, Michael Sori, Jennifer Scully, Lynnae Quick, Robert Grimm, Michael Zolensky, Michael Bland, Debra Buczkowski, Carol Raymond, Amanda Hendrix, Thomas Prettyman, Yasuhito Sekine, Timothy Titus, David Williams, Paul Backes, Laura Barge, Anton Ermakov, Andrew Galassi, Scott Moreland, and Kris Zacny
- Subjects
Lunar And Planetary Science And Exploration ,Exobiology - Abstract
Dwarf planet Ceres is a compelling target for future exploration because it hosts at least regional brine reservoirs and potentially ongoing geological activity. As the most water-rich body in the inner solar system, it is a representative of a population of planetesimals that were likely a significant source of volatiles and organics to the inner solar system. Here we describe possible medium-class (around $1 billion) mission concepts that would determine both Ceres’ origin and its current habitability potential. Habitability is addressed through a combination of geological, geophysical, and compositional investigations by (i) searching for evidence from orbit of past and ongoing geological activity near landforms interpreted as brine-driven volcanic structures and (ii) probing the brine distribution below one of these regions with electromagnetic sounding (in situ). Two approaches were considered for compositional measurements, which address both habitability and origins: (1) in situ exploration at two sites and (2) sample return from a single site. Both concepts targeted material at Occator crater, which is one of the youngest features on Ceres (∼20 Ma) and a site rich in evaporites evolved from recently erupted brine sourced from a region >35 km deep. We conclude that a sample return architecture from these young evaporite deposits offers greater science return by enabling high-resolution analysis of organic matter (trapped in salt minerals) and isotopes of refractory elements for a similar cost and less science risk than in situ analyses. This manuscript describes the six science objectives and the two implementation concepts considered to achieve those objectives.
- Published
- 2022
- Full Text
- View/download PDF
122. Are we alone in the universe?
- Author
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Tan, Lucas
- Published
- 2022
123. Targeting mixtures of jarosite and clay minerals for Mars exploration.
- Author
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HINMAN, NANCY W., BISHOP, JANICE L., GULICK, VIRGINIA C., DETTMANN, J. MICHELLE KOTLER, MORKNER, PAIGE, BERLANGA, GENESIS, HENNEBERGER, RUTH M., BERGQUIST, PETER, RICHARDSON, CHARLES DOC, WALTER, MALCOLM R., MACKENZIE, LINDSAY A., ANITORI, ROBERTO P., and SCOTT, JILL R.
- Subjects
- *
PROSPECTING , *JAROSITE , *CARBON in soils , *ORGANIC compounds , *HYDROTHERMAL alteration - Abstract
Terrestrial thermal environments can serve as analogs for subsurface environments in the search for life because they regularly host microbial communities, which may leave behind biosignatures. This study focused on an acid-sulfate hydrothermal site as an analog for a potentially habitable environment on Mars. A weathered boulder in the thermal area was dissected, revealing an interior marked with disconnected horizons of differently colored materials, very low pH, and increasing temperature. The mineralogy comprised weathering products from andesite (kaolinite, quartz, clinoptilolite) along with sulfate salts (alunite, jarosite, tschermigite, and copiapite) formed by oxidation of sulfide and ferrous iron. Characterization of organic matter in this boulder and several soil samples yielded interesting but surprising results. Both mass spectrometry and Raman spectroscopy identified organic compounds in portions of the soils and the boulder. Jarosite-associated samples showed more numerous and diverse organic signatures than did Al-bearing silicate samples, despite the lower total organic carbon content of the jarosite-associated soils (0.69 ± 0.07 wt% Corg) compared to the Al-bearing samples (1.28 ± 0.13 wt% Corg). Results from our geochemical, mineralogical, and spectroscopic study of hydrothermal alteration products and salts inform the heterogeneous distribution of inorganic and organic materials that could delineate habitats and demonstrate the limits on organic matter detectability using different analytical techniques. Furthermore, we relate our measurements and results directly to current and upcoming martian missions, and we provide recommendations for detection and characterization of minerals and organics as biosignatures on Mars using instruments on future missions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
124. A lingering local exopshere created by a gas plume of a lunar lander
- Author
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W.M. Farrell, P. Prem, O.J. Tucker, D.M. Hurley, B.A. Cohen, and M. Benna
- Subjects
Exobiology ,Lunar And Planetary Science And Exploration - Abstract
We model the expected local exosphere created by outgassing from a lunar lander plume water deposit located adjacent to a lunar lander. We assume the landing is near dawn within Lacus Mortis at 45oN. We consider a set of water desorption scenarios especially focusing on the water-surface desorption activation energy that can possess a distribution of energy states. Our initial simulation starts with a deposition surface having 1020 water molecules per square meter in a 2 km × 2 km region where 90% of the water is retained by weak water-water sorption interactions and 10% are bound by water-regolith sorption interactions. We find that the loosely bound water molecules in water-water interactions quickly desorb within hours after landing. However, water molecules bound to surface sites having a desorption activation greater than 0.7 eV were found to be retained until the source region rotated to later local times (i.e., surface temperature becomes relatively high). We found such time-delayed desorption leads to a tenuous but lingering exosphere emitted from the lander plume deposit region for many 10's of hours after landing. We also adjusted the initial condition by considering different landing local times and considered a case where 100% of the water is bound by water-regolith interactions (mimicking a porous regolith).
- Published
- 2021
- Full Text
- View/download PDF
125. Terrestrial Planet Optical Phase Curves: I. Direct Measurements of the Earth
- Author
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Roderick De Cock, Timothy A Livengood, Daphne M Stam, Carey M Lisse, Tilak Hewagama, and L Drake Deming
- Subjects
Astronomy ,Exobiology - Abstract
NASA’s EPOXI mission used the Deep Impact spacecraft to observe the disk-integrated Earth as an analog to terrestrial exoplanets’ appearance. The mission took five 24 hr observations in 2008–2009 at various phase angles(57°.7–86°.4)and ranges(0.11–0.34 au), of which three equatorial(E1, E4, E5)and two polar(P1, North and P2,South). The visible data taken by the HRIV instrument ranges from 0.3 to 1.0μm, taken trough seven spectral filters that have spectral widths of about 100 nm, and which are centered about 100 nm apart, from 350 to 950 nm. The disk-integrated, 24 hr averaged signal is used in a phase angle analysis. A Lambertian-reflecting, spherical planet model is used to estimate geometric albedo for every observation and wavelength. The geometric albedos range from 0.143(E1, 950 nm)to 0.353(P2, 350 nm)and show wavelength dependence. The equatorial observations have similar values, while the polar observations have higher values due to the ice in view. Therefore, equatorial observations can be predicted for other phase angles, but(Earth-like)polar views(with ice)would be underestimated.
- Published
- 2021
- Full Text
- View/download PDF
126. Origins of Life : A Cosmic Perspective
- Author
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Douglas Whittet and Douglas Whittet
- Subjects
- Exobiology, Life--Origin
- Abstract
Origins of Life: A Cosmic Perspective presents an overview of the concepts, methods, and theories of astrobiology and origins of life research while presenting a summary of the latest findings. The book provides insight into the environments and processes that gave birth to life on our planet, which naturally informs our assessment of the probability that has arisen (or will arise) elsewhere. In addition, the book encourages readers to go beyond basic concepts, to explore topics in greater depth, and to engage in lively discussions. The text is intended to be suitable for mid- and upper-level undergraduates and beginning graduate students and more generally as an introduction and overview for researchers and general readers seeking to follow current developments in this interdisciplinary field. Readers are assumed to have a basic grounding in the relevant sciences, but prior specialized knowledge is not required. Each chapter concludes with a list of questions and discussion topics as well as suggestions for further reading. Some questions can be answered with reference to material in the text, but others require further reading and some have no known answers. The intention is to encourage readers to go beyond basic concepts, to explore topics in greater depth, and, in a classroom setting, to engage in lively discussions with class members.
- Published
- 2017
127. Lebensraum Universum : Einführung in die Exoökologie
- Author
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Aleksandar Janjic and Aleksandar Janjic
- Subjects
- Exobiology
- Abstract
Dieses Buch führt in Fragestellungen der Astrobiologie und Exoökologie ein und vermittelt einen umfassenden Überblick über die aktuellsten Forschungsergebnisse, vergangenen Rückschläge und zukünftigen Missionen der führenden Raumfahrtorganisationen. Unter astrophysikalischen, geo- und bioökologischen Gesichtspunkten werden dem Leser exotische Welten und deren Bewohner präsentiert, welche unsere irdischen Vorstellungen auf den astronomischen Maßstab erweitern und das Phänomen Leben unter neuem Sternenlicht erstrahlen lassen.Werden wir in diesem Jahrhundert außerirdisches Lebensformen finden? Und nach welchen Biosignaturen auf fernen Himmelskörpern sollten wir suchen, um extraterrestrische Ökosysteme aufspüren zu können?
- Published
- 2017
128. Earths of Distant Suns : How We Find Them, Communicate with Them, and Maybe Even Travel There
- Author
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Michael Carroll and Michael Carroll
- Subjects
- Habitable planets, Exobiology
- Abstract
Based on the latest missions results and supported by commissioned artwork, this book explores the possible lessons we may learn from exoplanets. As the number of known Earth-like objects grows significantly, the author explores what is known about the growing roster of'pale blue dots'far afield. Aided by an increased sensitivity of the existing observatories, recent discoveries by Keck, the Hubble Space Telescope, and Kepler are examined. These findings, once thought to be closer to the realm of science fiction, have fired the imaginations of the general public as well as scientists.All of us are mesmerized by the possibility of other Earth-like worlds out there. Author Michael Carroll asks the tough questions of what the expected gain is from identifying these Earth analogs spread across the Universe and the reasons for studying them. Potentially, they could teach us about our own climate and Solar System. Also explored are the more remote options of communication between or even travel to these distant yet perhaps not so dissimilar worlds.
- Published
- 2017
129. Life Through Time and Space
- Author
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Wallace Arthur and Wallace Arthur
- Subjects
- Life on other planets, Exobiology, Human evolution, Life--Origin, Evolution, Developmental biology, Extraterrestrial anthropology
- Abstract
All humans share three origins: the beginning of our individual lives, the appearance of life on Earth, and the formation of our planetary home. Life through Time and Space brings together the latest discoveries in both biology and astronomy to examine our deepest questions about where we came from, where we are going, and whether we are alone in the cosmos.A distinctive voice in the growing field of astrobiology, Wallace Arthur combines embryological, evolutionary, and cosmological perspectives to tell the story of life on Earth and its potential to exist elsewhere in the universe. He guides us on a journey through the myriad events that started with the big bang and led to the universe we inhabit today. Along the way, readers learn about the evolution of life from a primordial soup of organic molecules to complex plants and animals, about Earth's geological transformation from barren rock to diverse ecosystems, and about human development from embryo to infant to adult. Arthur looks closely at the history of mass extinctions and the prospects for humanity's future on our precious planet.Do intelligent aliens exist on a distant planet in the Milky Way, sharing the three origins that characterize all life on Earth? In addressing this question, Life through Time and Space tackles the many riddles of our place and fate in the universe that have intrigued human beings since they first gazed in wonder at the nighttime sky.
- Published
- 2017
130. Cosmic Womb : The Seeding of Planet Earth
- Author
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Chandra Wickramasinghe, Ph.D, Robert Bauval, Chandra Wickramasinghe, Ph.D, and Robert Bauval
- Subjects
- Exobiology, Life--Origin, Life (Biology), Life on other planets
- Abstract
Compelling evidence that life, intelligence, and evolution on Earth were seeded by comets and cosmic intelligence • Explains how life first came from interstellar dust and comets and how later arrivals of cosmic dust and comets spurred evolution • Explores the possibility that universal knowledge may be stored in human DNA and how ancient cultures may have known a way to retrieve this knowledge • Reveals new discoveries about the dimensions of the Great Pyramid of Giza All ancient cultures link humanity's origins to the heavens. The Egyptians, for example, were adamant that their ancestors came from the stars of Orion and Sirius. Today, however, religion and science assert that life arose spontaneously here on Earth. Did the ancients know our true cosmic origins? Have they left us clues? Expanding on the panspermia theory developed with the celebrated astronomer Sir Fred Hoyle--namely that the building blocks of life were imported to Earth by comets in the distant past--Chandra Wickramasinghe and Robert Bauval explore the latest findings in support of a cosmic origin for humanity. They detail the astrobiological discoveries of organic molecules deep in space, how microbes are incredibly resistant to the harshest conditions of space--enabling the transfer of genes from one star system to another, and the recent recovery of microorganisms from comets still in space. They argue that the universe was “born” and preset with the blueprint of life and that the cosmos must be teeming with lifeforms far older and perhaps far more developed than us. They show how life arrived on our planet in the form of interstellar dust containing alien bacteria approximately 3.8 billion years ago and how later comets, meteoroids, and asteroids brought new bacterial and viral genetic material, which was vital for evolution. Using the latest advances in physics, cosmology, and neuroscience, the authors explore how universal knowledge may be stored in human DNA and cells, and they postulate that ancient cultures, such as the pyramid builders of Egypt and the temple builders of India, may have known a way to retrieve this knowledge. Sharing new discoveries from experienced architects, engineers, and mathematicians, they show how the Great Pyramid is a three-dimensional mathematical equation in stone, bearing a potent message for humanity across time and space about who we are and where we come from.
- Published
- 2017
131. The Nature of Life and Its Potential to Survive
- Author
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David S. Stevenson and David S. Stevenson
- Subjects
- Life (Biology), Life--Origin, Exobiology
- Abstract
This book looks at the persistence of life and how difficult it would be to annihilate life, especially a species as successful as humanity. The idea that life in general is fragile is challenged by the hardiness of microbes, which shows that astrobiology on exoplanets and other satellites must be robust and plentiful. Microbes have adapted to virtually every niche on the planet, from the deep, hot biosphere, to the frigid heights of the upper troposphere. Life, it seems, is almost indestructible. The chapters in this work examine the various scenarios that might lead to the extermination of life, and why they will almost always fail. Life's highly adaptive nature ensures that it will cling on no matter how difficult the circumstances. Scientists are increasingly probing and questioning life's true limits in, on and above the Earth, and how these limits could be pushed elsewhere in the universe. This investigation puts life in its true astronomical context, with the reader taken on a journey to illustrate life's potential and perseverance.
- Published
- 2017
132. Structure of exoplanets
- Author
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Spiegel, David S, Fortney, Jonathan J, and Sotin, Christophe
- Subjects
Earth ,Planet ,Exobiology ,Extraterrestrial Environment ,Jupiter ,Models ,Theoretical ,Neptune ,Oceans and Seas ,gas giants ,hot Jupiters ,super-Earths ,astro-ph.EP - Abstract
The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our solar system are merely possible outcomes of planetary system formation and evolution, and conceivably not even especially common outcomes (although this remains an open question). Here, we review the diverse range of interior structures that are both known and speculated to exist in exoplanetary systems--from mostly degenerate objects that are more than 10× as massive as Jupiter, to intermediate-mass Neptune-like objects with large cores and moderate hydrogen/helium envelopes, to rocky objects with roughly the mass of Earth.
- Published
- 2014
133. Occurrence and core-envelope structure of 1–4× Earth-size planets around Sun-like stars
- Author
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Marcy, Geoffrey W, Weiss, Lauren M, Petigura, Erik A, Isaacson, Howard, Howard, Andrew W, and Buchhave, Lars A
- Subjects
Atmosphere ,Earth ,Planet ,Evolution ,Planetary ,Exobiology ,Helium ,Hydrogen ,Models ,Theoretical ,Origin of Life ,Solar System ,Spectrum Analysis ,Stars ,Celestial ,Telescopes ,Water ,extrasolar planets ,astrobiology ,SETI ,astro-ph.EP - Abstract
Small planets, 1-4× the size of Earth, are extremely common around Sun-like stars, and surprisingly so, as they are missing in our solar system. Recent detections have yielded enough information about this class of exoplanets to begin characterizing their occurrence rates, orbits, masses, densities, and internal structures. The Kepler mission finds the smallest planets to be most common, as 26% of Sun-like stars have small, 1-2 R⊕ planets with orbital periods under 100 d, and 11% have 1-2 R⊕ planets that receive 1-4× the incident stellar flux that warms our Earth. These Earth-size planets are sprinkled uniformly with orbital distance (logarithmically) out to 0.4 the Earth-Sun distance, and probably beyond. Mass measurements for 33 transiting planets of 1-4 R⊕ show that the smallest of them, R < 1.5 R⊕, have the density expected for rocky planets. Their densities increase with increasing radius, likely caused by gravitational compression. Including solar system planets yields a relation: ρ = 2:32 + 3:19 R=R ⊕ [g cm(-3)]. Larger planets, in the radius range 1.5-4.0 R⊕, have densities that decline with increasing radius, revealing increasing amounts of low-density material (H and He or ices) in an envelope surrounding a rocky core, befitting the appellation ''mini-Neptunes.'' The gas giant planets occur preferentially around stars that are rich in heavy elements, while rocky planets occur around stars having a range of heavy element abundances. Defining habitable zones remains difficult, without benefit of either detections of life elsewhere or an understanding of life's biochemical origins.
- Published
- 2014
134. Lipids as universal biomarkers of extraterrestrial life.
- Author
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Georgiou, Christos D and Deamer, David W
- Subjects
Cell Membrane ,Hydrocarbons ,Lipids ,Biological Markers ,Exobiology ,Extraterrestrial Environment ,Biomarkers ,Biomembranes ,Extraterrestrial life ,Astronomy & Astrophysics ,Astronomical and Space Sciences ,Geochemistry ,Geology - Abstract
In 1965, James Lovelock published a general statement, based on thermodynamic chemical equilibrium principles, about how to detect extant or extinct life on a planet other than Earth. Nearly 50 years later, it is possible to make such measurements with robotic missions such as current and future Mars rovers, and probes to sample icy plumes of Enceladus or Europa. We make a specific recommendation that certain characteristic patterns in the composition of lipid hydrocarbons can only result from a biological process, because the signal arises from a universal requirement related to lipid bilayer fluidity and membrane stability. Furthermore, the pattern can be preserved over millions of years, and instrumentation is already available to be incorporated into flight missions.
- Published
- 2014
135. A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars
- Author
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Grotzinger, JP, Sumner, DY, Kah, LC, Stack, K, Gupta, S, Edgar, L, Rubin, D, Lewis, K, Schieber, J, Mangold, N, Milliken, R, Conrad, PG, DesMarais, D, Farmer, J, Siebach, K, Calef, F, Hurowitz, J, McLennan, SM, Ming, D, Vaniman, D, Crisp, J, Vasavada, A, Edgett, KS, Malin, M, Blake, D, Gellert, R, Mahaffy, P, Wiens, RC, Maurice, S, Grant, JA, Wilson, S, Anderson, RC, Beegle, L, Arvidson, R, Hallet, B, Sletten, RS, Rice, M, Bell, J, Griffes, J, Ehlmann, B, Anderson, RB, Bristow, TF, Dietrich, WE, Dromart, G, Eigenbrode, J, Fraeman, A, Hardgrove, C, Herkenhoff, K, Jandura, L, Kocurek, G, Lee, S, Leshin, LA, Leveille, R, Limonadi, D, Maki, J, McCloskey, S, Meyer, M, Minitti, M, Newsom, H, Oehler, D, Okon, A, Palucis, M, Parker, T, Rowland, S, Schmidt, M, Squyres, S, Steele, A, Stolper, E, Summons, R, Treiman, A, Williams, R, Yingst, A, Team, MSL Science, Kemppinen, Osku, Bridges, Nathan, Johnson, Jeffrey R, Cremers, David, Godber, Austin, Wadhwa, Meenakshi, Wellington, Danika, McEwan, Ian, Newman, Claire, Richardson, Mark, Charpentier, Antoine, Peret, Laurent, King, Penelope, Blank, Jennifer, Weigle, Gerald, Li, Shuai, Robertson, Kevin, Sun, Vivian, Baker, Michael, Edwards, Christopher, Farley, Kenneth, Miller, Hayden, Newcombe, Megan, Pilorget, Cedric, Brunet, Claude, Hipkin, Victoria, and Léveillé, Richard
- Subjects
Bays ,Carbon ,Exobiology ,Extraterrestrial Environment ,Geologic Sediments ,Hydrogen ,Hydrogen-Ion Concentration ,Iron ,Mars ,Nitrogen ,Oxidation-Reduction ,Oxygen ,Phosphorus ,Salinity ,Sulfur ,Water ,MSL Science Team ,General Science & Technology - Abstract
The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, and phosphorus were measured directly as key biogenic elements; by inference, phosphorus is assumed to have been available. The environment probably had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars.
- Published
- 2014
136. Crop growth and viability of seeds on Mars and Moon soil simulants
- Author
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Wamelink G.W.W., Frissel J.Y., Krijnen W.H.J., and Verwoert M.R.
- Subjects
extra-terrestrial ,food production ,growth experiment ,regolith ,exobiology ,Agriculture ,Agriculture (General) ,S1-972 - Abstract
If humans are going to establish a base on the Moon or on Mars they will have to grow their own crops. An option is to use Lunar and Martian regolith. These regoliths are not available for plant growth experiments, therefore NASA has developed regolith simulants. The major goal of this project was to cultivate and harvest crops on these Mars and Moon simulants. The simulants were mixed with organic matter to mimic the addition of residues from earlier harvests. Ten different crops, garden cress, rocket, tomato, radish, rye, quinoa, spinach, chives, pea and leek were sown in random lines in trays. Nine of the ten species grew well with the exception of spinach. It was possible to harvest edible parts for nine out of ten crops. The total biomass production per tray was highest for the Earth control and Mars soil simulant and differed significantly from Moon soil simulant. The seeds produced by three species were tested for germination (radish, rye and cress). The germination on Moon soil simulant was significantly lower in radish than for the Earth control soil.
- Published
- 2019
- Full Text
- View/download PDF
137. Microbial mediation of textures and minerals – terrestrial or parent body processes?
- Author
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Polgári Márta, Gyollai Ildikó, Bérczi Szaniszló, Veres Miklós, Gucsik Arnold, and Elemér Pál-Molnár
- Subjects
chondrite ,minerals ,alteration ,microbial ,exobiology ,fe-oxidizing microbes ,Astronomy ,QB1-991 - Abstract
Evolution of chondritic parent body is influenced by thermal, impact metamorphism and aqueous alteration, studied in Mező-Madaras, Knyahinya, Mócs and Nyírábrány in aspect of high resolution in situ textural, mineralogical and organic geochemical characteristics, using optical microscopy, FTIR-ATR and Raman spectroscopy. Our observations focused on Fe-containing opaque grains, glass, olivines and pyroxenes, which were well populated by micrometer-sized microbial filamentous elements in their boundary region within matrix and inside the minerals resembling mineralized microbially produced textures (MMPT), affecting 70-80 vol% of samples. In MMPT iron oxides (ferrihydrite, goethite), olivine, montmorillonite, kandite minerals and various hydrocarbon compounds were identified.
- Published
- 2019
- Full Text
- View/download PDF
138. Coexisting Quantum Gases in Earth’s Orbit
- Author
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Lena E Braatz
- Subjects
Space Sciences (General) ,Exobiology - Abstract
Summary: Ultracold atomic gases provide a unique tool for exploring the quantum nature of matter and for probing the foundations of modern physics. Researchers with NASA’s Cold Atom Lab (CAL) have now simultaneously produced gases of two atomic species (rubidium and potassium) in a uniquely quantum (wave-like) phase of matter called a Bose-Einstein condensate (BEC) for the first time in space. CAL scientists are using the unique micro gravity environment onboard the International Space Station to study interactions, molecule formation, and the emergence of structure and complexity in these coexisting dual-species gases at unprecedented low temperatures, for long times in free fall, and specifically in the absence of the perturbing force of gravity.
- Published
- 2021
139. A Novel Approach to Growing Gardens in Space
- Author
-
Florence Wee Ming Tan
- Subjects
Space Sciences (General) ,Exobiology - Abstract
A Project [eXposed Root On-Orbit Test System (XROOTS™)] to investigate techniques that can be scaled for crop production in microgravity, a NASA-sponsored Sierra Space team is developing soilless nutrient delivery and recovery technologies that will be demonstrated via plant tests aboard the International Space Station.
- Published
- 2021
140. Low Total Abundances and a Predominance of n-ω-Amino Acids in Enstatite Chondrites: Implications for Thermal Stability of Amino Acids in the Inner Solar System
- Author
-
Danielle N Simkus, Jose C Aponte Silva, Jamie E Elsila, Hannah L Mclain, Eric T Parker, Jason P Dworkin, and Daniel P Glavin
- Subjects
Exobiology - Abstract
Investigating the organic contents of enstatite chondrite meteorites may offer insights into both early inner solar system and early Earth chemistry. Enstatite chondrite meteorites have highly reduced and anhydrous compositions, and their bulk isotopic compositions closely resemble terrestrial values, suggesting that their parent body asteroids accreted within the inner protoplanetary disk and were a primary contributor during Earth’s late accretion (Javoy et al., 1995; Piani et al., 2020). Here, we present the first report of amino acids in enstatite chondrite meteorite samples. Three EH3 meteorites were analyzed (Dominion Range 14021, Larkman Nunatak 12001, and Larkman Nunatak 06252). The acid-hydrolyzed water extracts of the meteorites contained low abundances (1.5 – 215.9 pmol/g) of n-ω-amino acids (glycine, β-alanine, γ-amino-n-butyric acid (γ-ABA), δ-amino-n-valeric acid (δ-AVA), and ε-amino-n-caproic acid (ε-ACA)), but amino acids were not present above detection limits in the non-hydrolyzed samples. The low amino acid abundances and the predominance of n-ω-amino acids resembles amino acid distributions previously observed for thermally altered chondrites. These results suggest that the parent body asteroid was not conducive to the synthesis and/or preservation of α-amino acids, or free amino acids in general, and that EH3 chondrite-like material may not have been a primary contributor of diverse or abundant free amino acids to the early Earth.
- Published
- 2021
- Full Text
- View/download PDF
141. A Vision for the Next Generation of Spaceflight Microbiology: Human Health and Habitat Sustainability
- Author
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C Mark Ott, Cheryl A Nickerson, Roy Curtiss, James Wilson, Robert J C McLean, Neal Pellis, David Niesel, Joanna B Goldberg, Michael J Schurr, Kent Buchanan, Matthew Wargo, Jiseon Yang, Eleanor Blakely, Mark Shelhamer, Diego Bohorquez, Jared Broddrick, Victoria Castro, Phillip Stafford, Millicent E Goldschmidt, Heidi Kaplan, Erik Antonsen, and Eric Nauman
- Subjects
Aerospace Medicine ,Exobiology - Published
- 2021
142. The Hunt for Alien Life : A Wider Perspective
- Author
-
Peter Linde and Peter Linde
- Subjects
- Extraterrestrial beings, Exobiology, Life on other planets
- Abstract
Astronomer Peter Linde takes the reader through the story of the search for extraterrestrial life in a captivating and thought-provoking way, specifically addressing the new research that is currently devoted towards discovering other planets with life. He discusses the methods used to detect possible signals from other civilizations and the ways that the space sciences are changing as a result of this new field. “Are we alone?” is a mystery that has forever fascinated mankind, gaining momentum by scientists since the 1995 discovery of the existence of exoplanets began to inspire new ways of thinking in astronomy. Here, Linde tries to answer many philosophical questions that derive from this area of research: Is humanity facing a change of paradigm, that we are not unique as intelligent beings? Is it possible to communicate with others out there, and even if we can—should we?
- Published
- 2016
143. Cosmosapiens : Human Evolution From the Origin of the Universe
- Author
-
John Hands and John Hands
- Subjects
- Life--Origin, Exobiology
- Abstract
“A critical overview of scientific orthodoxy in an attempt to answer the fundamental questions “what are we?” and “why are we here?” (Kirkus Reviews). Specialist scientific fields are developing at incredibly swift speeds, but what can they really tell us about how the universe began and how we as humans evolved to play such a dominant role on Earth? John Hands's extraordinarily ambitious book merges scientific knowledge from multiple disciplines and evaluates without bias or preconception all the theories and evidence about the origin and evolution of matter, consciousness, and mankind. The result, a “pearl of dialectical reasoning” (Publishers Weekly, starred review), provides the most comprehensive account yet of current ideas such as cosmic inflation, dark energy, the selfish gene, and neurogenetic determinism. In the clearest possible prose, it differentiates the firmly established from the speculative and examines the claims of various fields to approach a unified theory of everything. In doing so it challenges the orthodox consensus in those branches of cosmology, biology, and neuroscience that have ossified into dogma. Its “shocking and invigorating” analysis (Daily Telegraph, A Best Science Book of 2015) reveals underlying patterns of cooperation, complexification, and convergence that lead to the unique emergence in humans of a self-reflective consciousness that enables us to determine our future evolution. This groundbreaking book is destined to become a classic of scientific thinking.Praise for Cosmosapiens “This is a truly exceptional piece of work.” —Tim Crane, Knightsbridge Professor of Philosophy, The University of Cambridge “A game-changer. In the tradition of Thomas Kuhn's The Structure of Scientific Revolutions, this lucidly written, penetrating analysis challenges us to rethink many things we take for granted about ourselves, our society, and our universe. It will become a classic.” —Peter Dreier, E P Clapp Distinguished Professor of Politics, Occidental College “Hands is an astute observer of recent trends in scientific ideas bold enough to point out what he sees as sense and nonsense and intelligently explain why. Even in cases where one might disagree, the arguments are thought-provoking.” —Paul Steinhardt, Albert Einstein Professor in Science, Princeton University
- Published
- 2016
144. Science, Culture and the Search for Life on Other Worlds
- Author
-
John W. Traphagan and John W. Traphagan
- Subjects
- Extraterrestrial anthropology, Anthropology, Astronomy, Life on other planets, Exobiology, Science--Social aspects
- Abstract
This book explores humanity's thoughts and ideas about extraterrestrial life, paying close attention to the ways science and culture interact with one another to create a context of imagination and discovery related to life on other worlds. Despite the recent explosion in our knowledge of other planets and the seeming era of discovery in which we live, to date we have found no concrete evidence that we are not alone. Our thinking about life on other worlds has been and remains the product of a combination of scientific investigation and human imagination shaped by cultural values--particularly values of exploration and discovery connected to American society.The rapid growth in our awareness of other worlds makes this a crucial moment to think about and assess the influence of cultural values on the scientific search for extraterrestrial life. Here the author considers the junction of science and culture with a focus on two main themes: (1) the underlying assumptions, many ofwhich are tacitly based upon cultural values common in American society, that have shaped the ways researchers in astrobiology and SETI have conceptualized the nature of their endeavor and represented ideas about the potential influence contact might have on human civilization, and (2) the empirical evidence we can access as a way of thinking about the social impact that contact with alien intelligence might have for humanity.
- Published
- 2016
145. Goldilocks and the Water Bears : The Search for Life in the Universe
- Author
-
Louisa Preston and Louisa Preston
- Subjects
- Habitable planets, Life on other planets, Exobiology
- Abstract
'Highly recommended'Financial TimesToday we know of only a single planet that hosts life: the Earth. But across a Universe of at least 100 billion possibly habitable worlds, surely our planet isn't the only one which, like the porridge Goldilocks sought, is just right for life?Astrobiologists search the galaxy for conditions that are suitable for life to exist, focusing on similar worlds located at the perfect distance from their Sun, within the aptly named'Goldilocks Zone'. Such a place might have liquid water on its surface, and may therefore support a thriving biosphere. What might life look like on other worlds? It is possible to make best-guesses using facts rooted in science, and by studying'extremophiles'– organisms such as the near-indestructible water bears, which can survive in the harshest conditions that Earth, and even space, can offer. Goldilocks and the Water Bears is a tale of the origins and evolution of life, and the quest to find it on other planets, on moons, in other galaxies, and throughout the Universe.
- Published
- 2016
146. All These Worlds Are Yours : The Scientific Search for Alien Life
- Author
-
Willis, Jon and Willis, Jon
- Subjects
- Life on other planets, Exobiology
- Abstract
Long before space travel was possible, the idea of life beyond Earth transfixed humans. In this fascinating book, astronomer Jon Willis explores the science of astrobiology and the possibility of locating other life in our own galaxy. Â Describing the most recent discoveries by space exploration missions, including the Kepler space telescope, the Mars Curiosity rover, and the New Horizons probe, Willis asks readers to imagine—and choose among—five scenarios for finding life. He encourages us to wonder whether life might exist within Mars's subsoil ice. He reveals the vital possibilities on the water-ice moons Europa and Enceladus. He views Saturn's moon Titan through the lens of our own planet's ancient past. And, he even looks beyond our solar system, investigating the top candidates for a “second Earth” in a myriad of exoplanets and imagining the case of a radio signal arriving from deep space. Covering the most up-to-date research, this accessibly written book provides readers with the basic knowledge necessary to decide where they would look for alien life.
- Published
- 2016
147. Editorial: Presentations at the 4th Workshop of the German Astrobiological Society (DAbG) on Astrobiology, 26–27 September 2019, Vienna, Austria
- Author
-
Tetyana Milojevic, Rosa De La Torre Noetzel, Oliver Strbak, and Dirk Schulze-Makuch
- Subjects
biosignatures ,habitability ,planets ,extremophiles ,exobiology ,astrobiology ,Astronomy ,QB1-991 ,Geophysics. Cosmic physics ,QC801-809 - Published
- 2021
- Full Text
- View/download PDF
148. Development of methodology for astrobiological sampling and analysis
- Author
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Phillips, Stephen James McGregor
- Subjects
576.839 ,Exobiology ,Work sampling - Abstract
The aim of the thesis is to improve the strategy for exploration of life on Mars and potentially other planetary bodies. This was achieved through the analysis of terrestrial analogues, particularly for targets on the surface of Mars. The search for evidence of life requires optimising several aspects including choice of samples, sample preparation and sample analysis. Analogues selected include snow/ice, evaporites and weathered volcanics. The determination of optimal parameters for extraction of biomarkers was performed on carbon-rich and carbon-poor samples using powdered limestone-shale pairs and on weathered basalt. For all samples, extraction efficiency increased (i) up to about 35°C then did not increase further with temperature; (ii) with smaller grain size; (iii) up to 24 hours extraction time then did not increase further. These data indicate that extraction protocols could be optimised in advance. Dry core drilling experiments showed that the resultant powder obscured visual observation, the range of particle sizes did not allow for the most efficient extraction of organics, and the core powder contained less biomarkers than the core as a result of heating. Extracts of melted Cairngorm snow/ice contained a range of n-alkanols up C18 and extracts of particulate matter contained n-alkanols up to C29. High molecular weight biomarkers are poorly soluble in water, emphasising the importance of optimising the extraction protocol. Samples of snow containing snow algae were successfully analysed for biological pigments using Surface Enhanced Raman Spectroscopy. The development of a bioluminescence assay for the detection of ATP was undertaken in the Cairngorm mountains during a summer and winter season. The detection of ATP was optimised by filtration. An assessment of the potential for site selection, on basalt, from visual parameters, proved that fracture density had the clearest correlation to ATP levels determined by bio-assay. Areas of high fracture density can be detected from Mars orbit, therefore such data could be used to highlight areas most likely to harbour microbes on Mars. The research has shown that terrestrial analogues can yield valuable information on how to optimise different stages of the analysis of a range of rock types that may be expected on Mars.
- Published
- 2011
149. Prevalence of Earth-size planets orbiting Sun-like stars.
- Author
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Petigura, Erik, Howard, Andrew, and Marcy, Geoffrey
- Subjects
astrobiology ,extrasolar planets ,Exobiology ,Extraterrestrial Environment ,Planets ,Stars ,Celestial ,Water - Abstract
Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administrations Kepler mission. We found 603 planets, including 10 that are Earth size ( ) and receive comparable levels of stellar energy to that of Earth (1 - 2 R[Symbol: see text] ). We account for Keplers imperfect detectability of such planets by injecting synthetic planet-caused dimmings into the Kepler brightness measurements and recording the fraction detected. We find that 11 ± 4% of Sun-like stars harbor an Earth-size planet receiving between one and four times the stellar intensity as Earth. We also find that the occurrence of Earth-size planets is constant with increasing orbital period (P), within equal intervals of logP up to ~200 d. Extrapolating, one finds 5.7(-2.2)(+1.7)% of Sun-like stars harbor an Earth-size planet with orbital periods of 200-400 d.
- Published
- 2013
150. Habitability Models for Astrobiology
- Author
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Abel Mendez, Edgard G Rivera-Valentin, Dirk Schulze-Makuch, Justin Filiberto, Ramses M Ramirez, Tana E Wood, Alfonso Davila, Chris Mckay, Kevin Ortiz Ceballos, Marcos Jusino-Maldonado, Nicole Torres-Santiago, Guillermo Nery, Rene Heller, Paul Byrne, Michael J Malaska, Erica Nathan, Marta Filipa Simoes, Andre Antunes, Jesus Martinez-Frias, Ludmilla Carone, Noam R Izenberg, Dimitra Atri, Humberto Itic Carvajal Chitty, Priscilla Nowajewski-Barra, Frances Rivera-Hernandez, Corine Brown, Kennda Lynch, David C Catling, Jorge I Zuluaga, Juan F Salazar, Howard Chen, Grizelle Gonzalez, Madhu Kashyap Jagadeesh, and Jacob Haqq-Misra
- Subjects
Exobiology ,Man/System Technology And Life Support - Abstract
Habitability has been generally defined as the capability of an environment to support life. Ecologists have beenusing Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth fromlocal to global scales. Astrobiologists have been proposing different habitability models for some time, with lit-tle integration and consistency among them, being different in function to those used by ecologists. Habitabilitymodels are not only used to determine whether environments are habitable, but they also are used to charac-terize what key factors are responsible for the gradual transition from low to high habitability states. Here wereview and compare some of the different models used by ecologists and astrobiologists and suggest how theycould be integrated into new habitability standards. Such standards will help improve the comparison and charac-terization of potentially habitable environments, prioritize target selections, and study correlations between habit-ability and biosignatures. Habitability models are the foundation of planetary habitability science, and the synergybetween ecologists and astrobiologists is necessary to expand our understanding of the habitability of Earth,the Solar System, and extrasolar planets.
- Published
- 2021
- Full Text
- View/download PDF
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