Microcosm experiments using microbial mats can be useful at times to understand mineral precipitation induced by microorganisms and their extracellular polymeric substances (EPS). Currently, the existing knowledge limits our ability to elucidate the interactions between microbes, which form communities as microbial mats, and minerals that precipitate in natural environments (e.g., lagoons, rivers, springs, soils). Much of the prior research did not consider entire microbial communities, despite recent evidence that microorganisms interact in a community-based way. This is especially relevant in extreme environments where the entire microbial communities are not yet known despite their relevance to biosignatures exploration on other planets. Here, we grew microbial mats on natural substrates in the laboratory to monitor changes in mat texture and mineral paragenesis. Several analytical techniques were used to compare mineral paragenesis in association with and without microbes. This paragenesis included major phases of chemical sedimentary deposits, such as gypsum, calcium carbonate, and some silicates, whose formation is traditionally linked to evaporative processes but was not in these experiments. In addition, some of the phases only precipitated within microbial mat samples and there were differences in mineral fabrics between mat samples and abiotic controls.
Introduction: It has been proposed that the recently discovered superphylum of Asgard archaea may represent a historical link/bridge between the Archaea and Eukarya. The arrangement of genes in genomes is a window to understand how organisms are related. In particular, the translation machinery and the genes that encode the same have a long evolutionary history. In order to gain further insight into the evolutionary position of the Asgard archaea, the genome order of ribosomal protein coding genes was analyzed. The Asgard archaea were compared with non-Asgard archaeal and bacterial genomes. Results: A core of co-occurring 15 genes belonging to the segment of the S10 and spc cluster (which are characterized and established as operons in Bacteria), was identified as conserved in gene order, arrangement and genome location in Asgard archaea, non-Asgard archaea and Bacteria. This core occurs as a complete set in the genomes of Lokiarchaeota MK-D1 (Candidatus Prometheoarchaeum syntrophicum), and Candidatus Odinarchaeota archaeon LCB_4. The genome assemblies of the other Asgard genomes are incomplete and occur in multiple contigs (>50) and hence this cluster is found in sections across contigs, with a section often either ending or beginning a contig. The cluster organization is indicative of co-occurrence, if the genome was complete. A second smaller cluster comprising the homologs of the most conserved genes of the bacterial S10 operon/cluster namely, uS10-uL3-uL4-uL23-uL2 occurs independently on the Asgard genomes, separate from the rest, a feature shared by many non-Asgard archaea as well. Other clusters. A new cluster L7ae-infB was identified to co-occur with the minor S24e-S27ae cluster in the two complete Asgard genomes. The L7ae-infB cluster co-occurs with the S24e-S27ae cluster in some (non-Asgard) Crenarchaeota (Desulfurococcacea) and Euryarchaeota (Methanobacteriaceae), while it co-occurs with the (Alpha operon) L18e cluster in some (non-Asgard) Euryarchaeota (Halobacteriaceae). Overall, the organization of the most universal and highly conserved S10 and spc cluster in Asgard archaea resembles that of the non-Asgard Thaumarchaeota and the DPANN group. References: Wang J et al (2009) Archaea, 2(4), 241–251. Da Cunha V et al (2017) Plos Genetics 13(6), e1006810. Bowman J. C. et al. (2020) Chem Rev, 120(11), 4848-4878.
The search for evidence of existing or extant Life (biosignatures) is a growing research topic and one of the main pillars of Astrobiology. There is significant interest in the search and exploration of new biosignatures, and increasing relevance of Potential Biosignatures. These are specific features that although consistent with biological processes can also be attributed to inanimate processes. Biogenic Metallic nanoparticles (MNPs), have been intensively studied and explored, yet their synthesis is not yet fully understood. Despite the lack of a systematic survey on this topic, it is well known that many microbes produce molecules with the capability of reducing metal ions. Given the wide diversity of such molecules, we can assume that all microbial life is capable of synthesizing them and, consequently, producing MNPs. Researchers agree that any existing or extant life on Mars or on other parts of the solar system, is (or was) likely microbial. Therefore, the detection of MNPs formation, when analyzing extraterrestrial samples (e.g., sediments, rocks), could be used to infer the presence of biological molecules and thus be employed as a new potential biosignature. Therefore, in short: yes, biogenic metallic nanoparticles have a great potential of being used as biosignatures.
Though fascinating and multi-disciplinary in scientific horizon, Astrobiology, till date has not managed to make a commendable mark in Indian academia which raises the need of not reformation but transformation in the education system. As per our recent survey, 30.88% of 2455 participants claimed to have heard about Astrobiology for the first time, 47.01% reported to have scant knowledge, and 22.12% were familiar. In addition, the data suggests that more than 77% of enthusiasts have no access to proper guidance and resources to pursue a career in Astrobiology. Hence, to tackle such issues, Spaceonova conducted free webinars and two day workshops in collaboration with 13 renowned institutions in India like IIST, DU, VIT etc., that impacted 3869 students across 700+ unique colleges. Such an initiative introduced them to the various career opportunities in the field of Astrobiology using Bioinformatics tools like Artemis and RasMol to carry out independent in-silico analysis. To carry the momentum forward, Spaceonova seeks to collaborate with various organisations to introduce research driven Astrobiology clubs, training programmes and diplomas in India to create an Astrobiology ecosystem, where limit tends to infinity. Here, we have discussed the required methodologies and blueprint to execute the same.
It is now understood that if life had ever erose on Mars, it might have been preserved in the simplest form. Therefore, studying the traces of simple life forms from the rock records of various Earth environments and climatic conditions perhaps helps to narrow down the region of interest while searching for life on the red planet. The Precambrian era covered almost 80% of Earth’s geologic history, witnessed the appearance of life on Earth and experienced prolonged extreme climatic events that delayed biological evolution. During this extreme period, primitive lifeforms such as microbial mats had a strong influence on sedimentation, and they facilitated the formation of a variety of mat-induced sedimentary structures (MISS) in siliciclastic and carbonate sedimentary environments. In the last two decades MISS have been identified from several Precambrian successions of India for example, Vindhyan, Marwar, Chhattisgarh and, Cuddapah Supergroup. In this study we tried to provide an updated catalogue based on the chronologic, stratigraphic and paleoenvironmental occurrences of MISS from the Indian Precambrian successions. We further explore their potential in understanding extreme habitability, searching biomarkers and biosignatures on Mars and propose a few potential sites for astrobiological research.
The discovery of exoplanets has altered our understanding of the universe. But, for the planets to show the possibility to harbour life in it or have biosignatures, it must have optimum physical, biological, geological and chemical conditions. There are two types of indicators of habitability: direct and indirect. The former indication is the presence of water and its stability on the surface of the planet. Thus, the reflection from the waterbody will lead to ‘glint’. Polarization of light is another alternative method to find water. The reflection, emission of radiation help us to characterize habitable zones. Indirect methods include the presence of CO2 and water vapour in the atmosphere, size of the planet and extent of axial tilt. The presence of magnetic fields and satellites revolving around the planet also play an important role. In this review article, we aim to provide a comprehensive explanation to the researches done till date to characterize habitable zones for exoplanets. The methods devised to retrieve results will also be discussed. Future prospects, the voids which could be amended are also elaborated. This could give cosmological research a new dimension, demonstrating that life is not limited to our planet.
Self-propelled motion is an agnostic biosignature that is observed widely, yet motility of microbes in their natural environments is sparsely studied. In this study we use a Digital Holographic Microscope (DHM) for in situ imaging of aquatic samples in extreme environments to investigate motility and morphology as biosignatures. Samples were collected from glaciovolcanic ice caves, glacial runoff, hot springs, and mixed glacial and hot spring samples.The transport and deposition of materials and heat from the volcanic subsurface in glaciovolcanic caves may be similar in some respects to the eruption processes of the plumes of Enceladus. Through different tracking methods, we identified concentrations of organisms, morphologies, swimming patterns, speeds, and turn angles. In every type of sample we looked we were able to identify motile organisms. Methods for distinguishing active swimming from Browian motion and drift are considered. Field work was done over two deployments in collaboration with the Thermal High-voltage Ocean-penetrating Research platform (THOR) science team and EELS robotics team. This work and these collaborations intend to inform future off-world extant life detection missions of the utility of DHM and motility as an investigation tool and biosignature, respectively.
The search for life in the universe can inspire students and members of the public alike. Three projects are described which provide an immersive experience with astrobiology. The first is teaching astrobiology to non-science majors in the virtual world Second Life. Second Life can support authentic learning and foster cross-cultural competencies. In the next iteration of the course, students will create simulations of exoplanet landscapes and architectures of exoplanetary systems. The second project is a virtual reality exhibit for education and outreach. It has models of major facilities in astronomy and space science in a virtual space. Users wear Oculus Quest headsets and use game controllers to navigate. Next additions to the VR space will be examples of exoplanet science and fully animated exoplanet systems. The third project is a new version of a multimedia performance piece called StellarScape, combining original electronic music, dance and simulations of star birth. A live dancer interacts with simulations via sensors. The next version is PlanetScape, where back-projected video is a series of realistically rendered exoplanet surfaces. The dancer undertakes a “hero’s journey,” experiencing the altered gravity and physical conditions of alien planets as they try to find their way home.
Since the famously inconclusive Viking missions, we have observed an increased desire to discover life outside the Earth. However, if we are to plan effective life-detection missions, then we must meet the challenge of classifying potential “agnostic” biosignatures (indicators of life or the absence of life). Agnostic refers to attempting to not use biosignatures that would bias towards Earth centric life standards, which would be “putting the answer in the question.” Machine learning techniques, specifically statistical classification already showed promising results in other fields. Applied to astrobiology, it may provide clarity on how different and independent measurements of the same biosignature affects your confidence in whether it is indicative of life. In this work, these algorithms were implemented to classify Raman spectra of potential biosignatures. Data was collected from public databases and individual research papers, processed, and then evaluated with several different algorithms. After thousands of simulations to allow the algorithms to test their classifications, we observed an 81% probability of correct classification when all the algorithms’ individual predictions were combined. These results demonstrate Raman spectroscopy’s potential for life-detection missions, and ability to improve upon a qualitative criterion for identifying indicative of life biosignatures.
In the field of Astrobiology, a quantitative approach has not been made to predict the number of extraterrestrial intelligent civilizations that may have existed on a habitable exoplanet as well their corresponding properties, such as intelligence, lifespan, and recovery time. Prior research indicates that numerous planetary systems within the Milky Way Galaxy are of over six billion years in age, implying many exoplanets, if sustainable to life, may have had several cycles of civilizations emergence and self-destruction, suggesting the ruins of advanced civilizations should be commonplace within the galaxy. We investigate this problem by utilizing statistical algorithmic simulations to predict and estimate the number of civilizations (both future and extinct) that may arise within an exoplanetary continuum, further generating the accompanying characteristics of said civilizations. Within the model, factors such as self-induced extinction/destruction, natural civilization decay, planetary disasters, and civilization rediscovery have been incorporated to examine the pathways a civilization can encounter. Our results corroborate the notion that on many of the older exoplanets in our galaxy, civilizations may have existed, however most have ultimately died out within a short period, further limiting the search for current extraterrestrial intelligence, but strengthening the approach of interstellar archeology.
As the leading astrobiology university student society, run by students, for students, at the University of Manchester Astrobiology Society we are embarked on a mission to spread the word about astrobiology, enrich the university community by delivering high-quality events and resources, and create a global network of students and young professionals that will become the astrobiologists of tomorrow. Ever since our foundation, we have gone beyond the classic student society activities by inviting world-renowned researchers, creating a dedicated careers program, or even organizing the first student-led online congress at the university. In addition, our innovation team always ensures that we use the latest tools and technologies to keep thriving in our ever-evolving world. In this sense, we have developed an all-in-one website where people interested in astrobiology can discover, learn and connect. Furthermore, we have also built a global community using social media, with almost 3000 followers spread over 17 countries. By leading by example, we want to spark change among student societies and for them to redefine their boundaries and to achieve bigger. At AbSciCon 2022 we aim to further pursue this goal, grow our network, share expertise, and learn from others.
Extremely halophilic archaea are microbes that thrive under very high salinities (>20% NaCl) and are almost exclusively placed in the class Halobacteria. In addition to their characteristic preference for high salinity and moderately high temperatures, many species of this class are resistant to desiccation, vacuum, and radiation, making them interesting targets for Astrobiological studies as model organisms and particularly relevant for the study of Mars, as highlighted by several authors. This class has a wide environmental range and includes species that live in salty biotopes such as salterns, salted foods, subterranean halite, lakes, or even in deep-sea brines in a list that includes several analogue sites. One current bottleneck of research with this group is the dispersed nature of data associated with its species. Our study partly addresses this by compiling phenotypic information and records of astrobiological experiments for all Halobacteria. We have established a database (HAPIE- Halophilic Archaea Phenotypic Information Explorer) that allows us to quickly compare different species as well as analyse trends and identify knowledge gaps and research opportunities. Our study identified gaps in coverage and knowledge (both at the level of taxonomy and range of tested parameters) and assisted us in defining new testing priorities.
Astrobiology as a field is not well known by the public, and is a difficult topic to introduce to the those who have never heard of it before. This presentation will showcase projects and experiences from a museum setting to explore how to best bring up such a complex field of science, and how astrobiologists can make their work as digestible as possible to the general public.
Unidentified Flying Objects (UFOs) appear frequently in science fiction and other public depictions of extraterrestrial technology. Recent interest in understanding UFOs, also known as Unidentified Aerial Phenomenon (UAP), has increased due to a recent report published by the U.S. Department of Defense that confirmed the detection of several UAP. However, actually identifying such objects remains challenging because “sociocultural stigmas and sensor limitations remain obstacles to collecting data on UAP” according to the report. In this presentation, we discuss the challenges posed by popular conceptions of UAP to genuine scientific inquiry using examples from Carl Sagan’s archives. This discussion is intended to engage astrobiologists in thinking critically about the differences between scientific inquiry of a genuinely unknown phenomenon and non-scientific popular speculations about the identity of UAP.
The ribosome is a universal molecular machine (comprised of RNA and proteins) which translates the message from the genome into proteins (polymers of amino acids) in biology. Similar to how Flight and Cockpit voice recorders record and preserve an aircraft’s flight history, the ribosome has recorded signatures of its evolution. Tapping this resource is important for understanding the origins of life. The electrostatic properties/net positive charge(s) of ribosomal proteins (RPs) stabilize interactions with the negatively charged ribosomal RNA (rRNA) and influence the assembly and folding of ribosomes. A high percentage of RPs from extremely halophilic archaea are known to be acidic/negatively charged. Recently the net charges (at pH 7.4) of the RPs from a highly conserved cluster of RPs were found to have an inverse relationship with the halophilicity/halotolerance (ability to survive under salt conditions) levels in bacteria and archaea. In non-halophilic bacteria, these RPs are generally basic, contrasting with the acidic proteomes of the extreme halophiles. We explore the use of a new mathematical modeling technique based on interaction graphs to provide a systematic understanding of the structural differences in the Large Subunit (LSU) of the bacterium Escherichia coli and that of the extremely halophilic archaeon Haloarcula marismortui.
Earth’s atmosphere underwent an irreversible, and geologically sudden, change approximately 2.5 billion years ago from oxygen free, to oxygenated, called the Great Oxidation Event (GOE). This change was driven by the evolution of a new form of photosynthesis which produced molecular oxygen as a byproduct. The group of bacteria in which this evolved, Cyanobacteria, are the only organisms to independently harness this form of photosynthesis. While we know that by the time of the GOE, Cyanobacteria were present, we do not know if they were present before the GOE. It has been proposed that Cyanobacteria were restricted to freshwater environments for hundreds of millions of years before the GOE, and only when they were able to inhabit the oceans did the GOE occur. We address this hypothesis by surveying the literature to understand how modern cyanobacteria respond to changes in salinity, as well as running a 1000 generation evolution experiment. We find evidence that just because a cyanobacterial species is found in freshwater does not mean it cannot live in marine salinities, and vice versa. Additionally, we find that prolonged exposure to a different salinity does not result in loss of ability to grow in the ancestral salinity.
Experimental studies of the interactions between biomolecules and minerals under conditions simulating harsh planetary environments provide key insights into possible prebiotic processes and the search for life. Despite protection from cosmic rays, UV, and oxidative degradation, buried biosignatures may undergo diagenetic processes that decrease the concentration of organic matter. Additionally, other degradation mechanisms occur as a result of elevated temperatures, pressures, mineral-organic interactions, and fluid/brine processes. In this study, we aim to provide a fuller understanding of preservation potential by considering several variables, including pressure, temperature, the mineral matrix environment, and fluid chemistry (salinity, pH, composition). This research expands previous anhydrous work to investigate the influence of lower pressure regimes, especially in a combined fluid/brine environment with various mineral matrices. To test the preservation potential of various biomolecules, we subjected samples to temperature, pressure, fluid, and mineral matrix conditions representative of different environmental stressors. The starting materials included: 1) isolated organic compounds added to various mineral standards, 2) An endolithic and microbe-rich natural calcite deposited from a CO2-rich hot spring, 3) cyanobacteria necromass. Experiments were conducted in three different devices 1) a piston-cylinder press reaching up to 15 kbar and 550 °C, 2) high-volume batch reaction vessels generating up to 15 MPa pressure and 80 °C, and 3) ambient pressure, high temperature furnaces. Samples were analyzed by GC-MS and LC-MS, while ICP-MS, XRD, and Raman were used for additional characterization. The influence of pressure can be clearly identified. Similarly, fluid transport, complex thermal degradation, and oxidation mechanisms are identified.
Computational software for planetary science and astrobiology is vital for understanding how complex systems interact, and for the analysis of sparse spacecraft data. PlanetProfile is an open source framework for modeling the interior of planetary bodies, especially ocean worlds, and is available in Matlab. We have rebuilt PlanetProfile in Python to improve its accessibility, as Python is free and widely used in scientific computing. PlanetProfile features such as the calculation of induced magnetic fields and seismic properties permit wider availability of these important tools for research purposes. An upcoming release of PlanetProfile contains the converted and streamlined software. New features such as a graphical user interface are in development that will support new users in taking advantage of these valuable tools.