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Identifying the sources of high-energy cosmic neutrinos has been a challenge. Considering frequentist and Bayesian arguments, as well as the special conditions found in neutrino astronomy, we discuss whether to believe current 3σ observations.

That the interstellar object 1I/2017 U1 (‘Oumuamua) could be an extraterrestrial artefact is an unorthodox hypothesis. From a philosophical perspective, however, the structure of the underlying argument for the hypothesis is flawed.

Astronomy and astrophysics in Vietnam are still in their infancy. Current efforts to stimulate interest in the general public, to foster the teaching of basic knowledge, and to develop research on frontline topics are described.

Exploring the hypothesis that life is present on Mars today is key to informing planetary protection issues at a pivotal time, with the clock ticking to return pristine samples before humans irrevocably alter the environment.

The 2020 COVID-19 pandemic forced a string of cancelled conferences, causing many organizers to shift meetings online, with mixed success. Seizing the opportunity, a group of researchers came together to rethink how the conference experience and collaboration in general can be improved in a more virtual-centric future.

The Pan-African School for Emerging Astronomers (PASEA) is an innovative short course for African university students, held by an African-led international collaboration. PASEA aims to build a critical mass of astronomers in Africa and exchange ideas about teaching across continents.

High-performance scientific satellites are currently the exclusive domain of government-funded agencies. The team behind the Twinkle Space Mission is developing a new class of small and sustainable science satellites that leverages recent innovations in the commercial space sector.

Earth’s exosphere is set to become increasingly crowded, with tens of thousands of commercial telecommunication satellites planned in the next few years. We need to ensure that technological and socio-economic advancements will not imperil scientific progress and humanity’s access to dark skies.

Astronomy research in Malaysia has progressed rapidly in the last few decades, with an increasing number of enthusiastic Malaysian astronomers working together to build new research groups and observing facilities, while establishing research networks both locally and globally.

Philanthropic donations are a significant contribution to the betterment of humankind, with a large percentage dedicated to science and education. Affordable small satellites may offer philanthropists the opportunity to give students and underprivileged communities access to small space telescopes.

The Space Academic Network made a case for a small-satellite programme for the United Kingdom to provide access to space, and a route for advancing science and technology; however, funding has not been forthcoming. The search for a killer argument for this widely supported programme continues.

The determination of the evolutionary stage for a supernova remnant is a demanding task. This guide for radio observers presents a relatively straightforward way to establish the evolutionary phase of newly observed supernova remnants.

Measuring the carbon emissions of the CFHT in 2019 reveals that the per employee emissions are 16.5 tCO₂e, six times above the recommendation of the Paris Agreement, with ~63% due to the electricity consumption of the summit facility and ~25% to out-of-state air travel. Concerted efforts are underway to reduce this figure.

Analysing greenhouse gas emissions of an astronomical institute is a first step to reducing its environmental impact. Here, we break down the emissions of the Max Planck Institute for Astronomy in Heidelberg and propose measures for reductions.

The annual meeting of the European Astronomical Society took place in Lyon, France, in 2019, but in 2020 it was held online only due the COVID-19 pandemic. The carbon footprint of the virtual meeting was roughly 3,000 times smaller than the face-to-face one, providing encouragement for more ecologically minded conferencing.

Climate change is affecting and will increasingly affect astronomical observations, particularly in terms of dome seeing, surface layer turbulence, atmospheric water vapour content and the wind-driven halo effect in exoplanet direct imaging.

Computer use in astronomy continues to increase, and so also its impact on the environment. To minimize the effects, astronomers should avoid interpreted scripting languages such as Python, and favour the optimal use of energy-efficient workstations.

The Pacific Ocean Neutrino Experiment is a new initiative towards constructing a multi-cubic-kilometre neutrino telescope to expand our observable window of the Universe to the highest energies, and will be installed within the deep Pacific Ocean underwater infrastructure of Ocean Networks Canada.

During the last 15 years the number of astronomy-related papers published by scientists in Venezuela has been continuously decreasing, mainly due to emigration. If rapid corrective actions are not implemented, professional astronomy in Venezuela could disappear.

The historic launch of the first several hundred out of 12,000 planned Starlink satellites heralds the arrival of the era of ultra-large satellite constellations. If it will bring new opportunities or insurmountable challenges to astronomy will probably depend on whether you are conducting your observations in space or from the surface of the Earth.