Volume 7 Issue 4, April 2023

What is the link between the discovery of the relativistic expanding Universe and British imperialism? A public panel debate in the early days of relativistic cosmology shows how fundamental scientific research, whether there are obvious political stakeholders (like biosecurity and climate) or not, runs real-time risks of being repurposed for political ends.

The arrangement of dwarf galaxies in a thin plane surrounding the Milky Way has been thought to contradict the prevailing cosmological model of cold dark matter in the Universe. New work suggests that this arrangement may just be a temporary alignment, bringing our galaxy back into agreement with theoretical expectations once the radial distribution of satellites is taken into account.

A probabilistic machine learning-based framework for recognizing and predicting microbial landscape patterns at nested spatial scales was developed. The approach substantially increased the probability of detecting biosignatures when tested at a Martian analogue in the high Andes. This search tool has applications for detecting biosignatures on terrestrial or icy planets.

The exploration of small planetary bodies depends crucially on the success of anchoring robots. This Perspective takes us through the diverse challenges and technological innovations involved when making contact with unknown surfaces.

MicrOmega characterized the population of carbonates detected in the bulk components and in individual grains of the Ryugu returned samples. Two main carbonate families are detected, which were likely formed via two distinct processes at different stages in the early Solar System.

The returned samples from Hayabusa2 show that C-type asteroid Ryugu experienced various steps of mineralogical alteration within only 1–2 million years after accretion.

A nested orbit-to-ground approach for microbial landscape patterns at different scales, tested in the high Andes, provides a machine learning-based search tool for detecting biosignatures on terrestrial planets.

Hydrocarbons containing five-membered rings have recently been detected in the cold Taurus Molecular Cloud. Here the authors show that the reaction involving ortho-benzyne and the methyl radical plays a critical role in the bottom-up formation of these complex hydrocarbons.

Using JWST, the molecules seen in planetary atmospheres can be traced back to their cold origins in ices formed in dense interstellar clouds, before the onset of star formation, revealing that chemical diversity and complexity is achieved early.

From an end-to-end model that characterizes the host galaxy, environment and progenitors of the binary neutron star merger gravitational wave event GW170817, the preferred solution is 2 low-metallicity stars of >10 solar masses that were born during Cosmic Noon, interacted repeatedly and remained bound even through 2 supernovae.

A few missing photons in Fermi Gamma-ray Space Telescope observations lead to robust neutron star mass measurements in eclipsing millisecond pulsar binaries, ruling out an ultra-massive pulsar in the original Black Widow system.

Analysis of a large galaxy sample shows that black hole activity is greater in galaxies in which the stellar and gas kinematics are misaligned. This observation suggests that the misalignment, driven by external gas accretion, fuels the central supermassive black holes.

A study of the emission variability of roughly 5,000 of the brightest quasars supports the presence of an optically thick yet geometrically thin accretion disk, and may provide a means of measuring the size and inclination of the disk.

The ‘plane of satellite galaxies’ surrounding our Milky Way seemed to defy dark matter theory for 40 years. Observations now suggest that the alignment is transient, while new simulations form similar structures far more often than previously thought.

A state-of-the-art machine-learning method combs a 480-h-long dataset of 820 nearby stars from the SETI Breakthrough Listen project, reducing the number of interesting signals by two orders of magnitude. Further visual inspection identifies eight promising signals of interest from different stars that warrant further observations.

ERIS takes over from and improves upon the key functionalities of the VLT’s former NACO and SINFONI instruments.