Astrobiology is a scientific endeavour involving great uncertainties. This could justify intellectual risk-taking associated with research that significantly deviates from the mainstream, to explore new avenues. However, little is known regarding the effect of such maverick endeavours. To better understand the need for more or less risk in astrobiology, we investigate to what extent high-risk / high-impact research contributes to breakthrough results in the discipline. We gathered a sample of the most impactful astrobiology papers of the past 20 years and explored the degree of risk of the research projects behind these papers via contact with the corresponding authors. We carried out interviews to explore how attitudes towards risk have played out in their work, and to ascertain their opinions on risk-taking in astrobiology. We show the majority of the selected breakthrough results derive from endeavours considered medium- or high-risk, risk is significantly correlated with impact, and most of the discussed projects adopt exploratory approaches. Overall, the researchers display a distribution of attitudes towards risk from the more cautious to the more audacious, and are divided on the need for more risk-taking in astrobiology. Our findings ultimately support the explicit implementation of a risk-balanced portfolio in astrobiology.

Although astrobiology studies how life functions and evolves, ecology is still largely overlooked in astrobiology research. Here we present an argument for astroecology, a merger of ecology and astrobiology, a self-aware scientific endeavour. Ecology is rarely mentioned in influential documents like the NASA Astrobiology Strategy (2015), and terms such as ‘niche’ can end up being used in a less precise fashion. As ecology deals with sequential levels of organization, we suggest astrobiologically-relevant problems for each of these levels. Organismal ecology provides ecological niche modelling, which can aid in evaluating the probability that Earth-like life would survive in extraterrestrial environments. Population ecology provides a gamut of models on the consequences of dispersal, and if lithopanspermia can be validated as a form of space dispersal for life, then metabiospheres and similar astrobiological models could be developed to understand such complex structure and dynamics. From community ecology, the discussion of habitability should include the concept of true vacant habitats (a misnomer, perhaps better called ‘will-dwells’) and contributions from the blossoming field of microbial ecology. Understanding ecosystems by focusing on abiotic properties is also key to extrapolating from analogue environments on Earth to extraterrestrial ones. Energy sources and their distribution are relevant for ecological gradients, such as the biodiversity latitudinal gradient – would tropics be species-rich in other inhabited planets? Finally, biosphere ecology deals with integration and feedback between living and non-living systems, which can generate stabilized near-optimal planetary conditions (Gaia); but would this work for other inhabited planets? Are there ‘strong’ (like Earth) and ‘weak’ (perhaps like Mars) biospheres? We hope to show ecology can contribute relevant ideas to the interdisciplinary field of astrobiology, helping conceptualize further levels of integration. We encourage new partnerships and for astrobiologists to take ecology into account when studying the origin, evolution and distribution of life in the universe.

In this study, we surveyed a total of 245 people about unidentified anomalous phenomena (UAP), 93 who directly witnessed UAP. Paying special attention to the psychological impact of UAP, our study survey covered different aspects, including opinions on official UAP releases, the scientific approach to the phenomena and the search for extra-terrestrial intelligence. This study found that UAP had a clear psychological impact on witnesses, with a transformative effect, and a benign form of a non-pathological obsessive-like interest in the topic we defined as the UAP deep psychological engagement triad. This deep psychological engagement triad is characterized by UAP topic being present in a witness's mind daily, with a self-recognized interest and appreciation for the topic and a need to talk about UAP topic, not necessarily the event they experienced. UAP appear to have a very specific impact focused on extra-terrestrial aspects and the phenomena itself, which is experienced as a life-changing event by direct witnesses. These psychological aspects are quantitatively and qualitatively objectifiable, and further research is needed in this direction since all research efforts appear currently focused on the physical aspects of these phenomena.

Interplanetary spacecraft are built in a spacecraft assembly facility (SAF), a clean room designed to reduce microbial contamination that could confound life detection missions or influence native ecosystems. The frigid hyperarid near-surface environment of Mars has ample hygroscopic Mg and Na salts of chloride, (per)chlorate and sulphate that may deliquesce to form dense brines, liquids with low water activity, and freezing points <0°C. The current study sought to define the climax microbial community after 6 mo of enrichment of SAF floor wipe samples in salt plains medium supplemented with 50% (w/v; ~2 M; aw = 0.94) MgSO4 or 20% (w/v; ~1.9 M; aw = 0.91) NaClO3. After 1 wk, 4 wk and 6 mo of incubation, metagenomic DNA extracts of the enriched SAF microbial community were used for high-throughput sequencing of 16S rRNA genes and subsequent phylogenetic analyses. Additionally, dozens of bacterial strains were isolated by repetitive streak-plating from the climax community after 6 mo of enrichment. Early in the enrichment, staphylococci greatly dominated and then remained abundant members of the community. However, actinobacteria succeeded the staphylococci as the dominant taxa as the cultures matured, including Arthrobacter, Brachybacterium and Brevibacterium. A diverse assemblage of bacilli was present, with Oceanobacillus being especially abundant. The SAF culture collection included representatives of Brachybacterium conglomeratum, Brevibacterium sediminis, Oceanobacillus picturae and Staphylococcus sciuri. These were characterized with biochemical and physiological tests, revealing their high salinotolerance. Shannon diversity indices were generally near 2, reflecting modest diversity at several levels of identity and the community structures were uneven throughout. However, minor members of the community seem capable of the ecosystem functions required for biogeochemical cycling. For instance, organisms capable of all the functions of the N cycle were detected. The microbial assemblage in SAFs is the most likely to be transported by spacecraft to another world. While individual microbial populations may exhibit the qualities needed for survival at the near-surface of Mars, certainly entire communities with the capacity for complete biogeochemical cycling, would have a greater chance of survival and proliferation.

Astrobiocentrism is a vision that places us in a scenario of confirmation of life in the universe, either as a second genesis or as an expansion of humanity in space. It manages to raise consistent arguments in relation to questions such as what would happen to knowledge if life were confirmed in the universe, how would this change the way we understand our place in the cosmos? Astrobiocentrism raises a series of reflections in the context of confirmed discovery, and it develops concepts that work directly with what would happen after irrefutable evidence has been obtained that we are not alone in space. Unlike biocentrism or ecocentrism, the astrobiocentric view is not limited to the Earth-centric perspective, and for it incorporates a multi-, inter- and transdisciplinary understanding. Therefore, the aim of this paper is to make a reflection on the astrobiocentric issues related to the challenges and problems of the discovery of life in the universe and the expansion of mankind into space. Here we explore some aspects of the transition from biogeocentrism to astrobiocentrism, astrobiosemiotics, homo mensura, moral community, planetary sustainability and astrotheology.

In a rapidly changing academic-scientific context, it is essential to adapt new learning strategies that foster the acquisition of new knowledge and the development of skills in future professionals, such as interacting synergistically with disciplines outside their own to execute projects successfully and comprehensively. The adaptation is only possible thanks to the inter and transdisciplinarity that Astrobiology has promoted since its inception. We use the term transdisciplinary for education that integrates different disciplines in a way to build new knowledge and increase the student's knowledge and skills. For this reason, this study aimed to demonstrate that an astrobiological stratospheric balloon launch project cultivates transdisciplinary awareness in participants: undergraduate university students in Lima, Peru. The sample consisted of 15 students from the following disciplines: biology, genetics, chemical engineering, physics, industrial engineering, agri-food engineering, forestry engineering, electronics engineering, mechatronics engineering, geology, geological engineering, philosophy, social communication, audiovisual communication and education. Using a semi-structured in-depth interview technique, experts validated the questions from the Universidad Nacional Mayor de San Marcos, Peru, and a matrix of meaning was constructed to classify the responses, ultimately obtaining the categories: contribution, complementarity and quantity. The participants' responses were processed and analyzed with Chat-GPT 3.5, revealing unanimous agreement that each participant's discipline contributed to the success of the balloon launch. To complement the qualitative interpretation of the results, a quantitative measurement was conducted to minimize subjective biases. Additionally, they gained knowledge and insights into other unfamiliar study subjects, collaborated to improve process quality, shared and harmonized their ideas to implement comprehensive solutions, and affirmed that their university education is often isolated or strictly focused on their specialization. In conclusion, experiences where different areas of knowledge converge in praxis, have the potential to awaken new technical, cognitive and communication skills in the individuals involved, utilizing astrobiological resources to invigorate and strengthen collective learning.

In situ elemental imaging of planetary surface regolith at a spatial resolution of 100s to 1000s of microns can provide evidence of the provenance of rocks or sediments and their habitability, and can identify post-depositional diagenetic alteration affecting preservation. We use high-resolution elemental maps and XRF spectra from MapX, a flight prototype in situ X-ray imaging instrument, to demonstrate this technology in rock types relevant to astrobiology. Examples are given for various petrologies and depositional/diagenetic environments, including ultramafic/mafic rocks, serpentinites, hydrothermal carbonates, evaporites, stromatolitic cherts and diagenetic concretions.

A few dozens of solutions to the Fermi paradox have been proposed in the past. The most relevant ones will be concisely discussed in this paper. They will be classified as follows: exceptionality solutions, annihilation solutions and communication barrier solutions. The argument will be advanced that all existing resolutions to the Fermi paradox are in their essence anthropocentric. The epistemological groundwork of anthropocentrism will be discussed. Conversely, in this paper, a non-anthropocentric solution to the Fermi paradox will be proposed: the ‘lasting human epistemological limitations solution’. This resolution to the Fermi paradox acknowledges that human epistemological capacities are limited to the degree that not only extraterrestrial forms of life may be unobservable to the human perceptive apparatus, but that universes may exist around humans with forms of life, inorganic matter or entities of any other type that humans are incapable of perceiving. In light of the revolutionary developments in theoretical physics, it is likely that in the future these developments will be reflected in increasingly non-anthropocentric solutions to the Fermi paradox.

The generation of organic compounds relevant to the origin of living beings is easily achieved if reducing conditions exist in the environment; however, proposed models of primitive atmospheres do not favour these conditions. This work considers the quantity and possible size of the cosmic bodies that could have impacted the Earth between 4.2 and 3.8 Ga. Different atmospheres (with gases such as CO2, CO, N2, CH4) were experimentally irradiated by an Nd-YAG laser (used to simulate the energy of a shock wave produced by the interaction of a cosmic body with the atmosphere). Although the main products are short-chain, saturated and unsaturated hydrocarbons, hydrogen cyanide (HCN) is the most abundant in some atmospheres. HCN is an important precursor of the organic molecules relevant to chemical evolution. According to our calculations, between 1023 and 1025 g of HCN could have been produced by the energy released to the atmosphere from the entry of cosmic objects between 4.2 and 3.8 Ga. Therefore, this shock wave energy could play an important role in the processes of chemical evolution.

Life as we know it requires the presence of liquid water and the availability of nutrients, which are mainly based on the elements C, H, N, O, P and S (CHNOPS) and trace metal micronutrients. We aim to understand the presence of these nutrients within atmospheres that show the presence of water cloud condensates, potentially allowing the existence of aerial biospheres. In this paper, we introduce a framework of nutrient availability levels based on the presence of water condensates and the chemical state of the CHNOPS elements. These nutrient availability levels are applied to a set of atmospheric models based on different planetary surface compositions resulting in a range of atmospheric compositions. The atmospheric model is a bottom-to-top equilibrium chemistry atmospheric model which includes the atmosphere–crust interaction and the element depletion due to the formation of clouds. While the reduced forms of CNS are present at the water cloud base for most atmospheric compositions, P and metals are lacking. This indicates the potential bio-availability of CNS, while P and metals are limiting factors for aerial biospheres.