Carbon reduction is an important process for Earth-like origins of life events and of great interest to the astrobiology community. In this paper, we have collected experimental results, field work and modelling data on CO and CO2 reduction in order to summarize the research that has been carried out particularly in relation to the early Earth and Mars. By having a database of this work, researchers will be able to clearly survey the parameters tested and find knowledge gaps wherein more experimentation would be most beneficial. We focused on reviewing the modelling parameters, field work and laboratory conditions relevant to Mars and the early Earth. We highlight important areas addressed as well as suggest future work needed, including identifying relevant parameters to test in both laboratory and modelling work. We also discuss the utility of organizing research results in such a database in astrobiology.

Using a simple, coarse-grained Poisson process model, we calculate – for seven types of astrophysical catastrophe – both their individual and combined threat to complex lifeforms (extraterrestrial intelligences (ETIs)) throughout the Milky Way Galaxy. In terms of cumulative effects, we calculate that ETIs are likely to be astrophysically driven extinct on timescales of roughly once every 100 million years. In terms of comparative effects, large bolide impactors represent the most significant type of astrophysical contribution to the galaxy-wide debilitation of hypothesized ETI civilizations. Nonetheless, we conclude that astrophysical existential threats – whether taken singly or in combination – are likely insufficient, alone, to explain the Fermi Paradox. Astrophysical catastrophes, while both deadly and ubiquitous, do not appear to be frequent enough to wipe out every species in the Galaxy before they can attain or utilize spacefaring status.

In this paper we consider a scenario in which Carl Sagan's Copernican principle is more likely than its negation. Thus, assuming that the existence of an extraterrestrial intelligence (ETI) is reasonably likely, the paper considers the possibility of an ETI that is unable to recognize humans as intelligent beings. The paper presents the rationale for such an assumption. It also discusses the possible consequences for humanity of such a scenario. In this paper, we argue why the scenario under discussion is actually more positive for humanity than a scenario in which ETI would be capable of recognizing humanity as an intelligent species. We also point to feminist approaches to SETI issues exposing the role played by the specific evolutionary and developmental context of potential ETI.

There is increased interest in exploring planetary bodies that have ocean worlds, and planetary protection (PP) practices for spacecraft are important to avoid harmful biological contamination of these sensitive environments. In the autumn of 2018 a diverse set of subject matter experts were assembled to examine the environmental input parameters (e.g. space radiation, Europa surface turnover) and biological input parameters that are referenced by the Europa Clipper project probabilistic risk model, to assess the < 1 × 10−4 probability of contamination requirement derived from NASA Procedural Requirements 8020.12D. A joint NASA–JPL lead workshop entitled, ‘Europa Clipper Planetary Protection Workshop’ was convened on 13–15 November 2018, to validate probability model input values, current Europa Clipper PP requirements and implementation strategy, and identify future PP research topics. The three objectives for the 3 day workshop were: (1) to validate the probability of contamination modelling framework for Europa Clipper PP; (2) to agree on probability of contamination model input values, or on a plan to derive/identify appropriate model inputs and (3) to develop workshop concurrence regarding future PP research plans and their priority. Workshop participants engaged in detailed scientific and engineering discussions focusing on Clipper mission objectives and trajectories, Europan ice shell geophysics and understanding the impact of initial microbial bioburdens and spacecraft cleanliness with all three objectives being successfully completed by the end of the workshop.

We address a recently posed question: ‘Why Do So Many Astronomy (and Astrobiology) Discoveries Fail to Live Up to the Hype?’ We expand it to cover hype within science in general. Our answer relies on working definitions of hype and skin in the game, as applied to research science, and a game theory model for the stability of cooperative science. Low skin in the game allows internal feedbacks, within the research science community, to initiate increased hype and a drift toward structural instability. The instability leads to the deterioration of cooperative equilibria, which further enhances hype. Along the drift, the number of results hyped as breakthroughs will increase and more claims will fail to live up to the hype. This can lead to the public perception that science is moving backwards and a shift in the perception of what scientists, and science, values. Although a hype instability can be initiated by external nudges, a bigger role is played by the internal dynamics of the system, i.e. the collective of working scientists. Corrections for a drift toward instability should, likewise, focus on internal structure. Proposed external shifts on how research is disseminated will add restrictions to a system that can do more harm than good.

The Astrobiology Graduate Conference (AbGradCon) is an annual conference both organized for and by early-career researchers, postdoctoral fellows, and students as a way to train the next generation of astrobiologists and develop a robust network of cohorts moving forward. AbGradCon 2021 was held virtually on 14–17 September 2021, hosted by the Earth-Life Science Institute (ELSI) of Tokyo Institute of Technology after postponement of the in-person event in 2020 due to the COVID-19 pandemic. The meeting consisted of presentations by 120 participants from a variety of fields, two keynote speakers, and other career-building events and workshops. Here, we report on the organizational and executional aspects of AbGradCon 2021, including the meeting participant demographics, various digital aspects introduced specifically for a virtual edition of the meeting, and the abstract submission and evaluation process. The abstract evaluation process of AbGradCon 2021 is unique in that all evaluations are done by the peers of the applicants, and as astrobiology is inherently a broad discipline, the abstract evaluation process revealed a number of trends related to multidisciplinarity of the astrobiology field. We believe that meetings like AbGradCon can provide a unique opportunity for students and early career researchers in astrobiology to experience community building, inter- and multidisciplinary collaboration, and career training and would be a welcome sight in other fields as well. We hope that this report provides inspiration and a basic roadmap for organizing future conferences in any field with similar goals.