Volume 8 Issue 4, April 2024

In response to concerns raised by the Navajo Nation on treating the Moon as a grave, NASA has a unique opportunity to advance the conversation with Indigenous communities regarding how we interact with space environments, and who gets to decide.

Computer simulations based on the prevailing cosmological model, ΛCDM, reproduce many observed properties of our Universe. But a study of coherent satellite motions in galaxy clusters yields discrepancies that challenge the definition of ‘today’.

The successful impact of NASA’s DART on Dimorphos, the moon of asteroid Didymos, has been analysed using advanced numerical simulations. The results reveal the asteroid’s low surface cohesion and rubble-pile structure, similar to what has been observed on asteroids Ryugu and Bennu.

The observed ‘radius valley’ — a dip in the distribution of exoplanet radii, which separates rocky super-Earths from larger sub-Neptunes — is at odds with current theories of planetary formation. New simulations that couple planet formation and evolution, and account for the orbital migration of planets that are largely composed of steam, are able to reproduce the valley feature.

High-mass stars in the Milky Way often exist in systems of two or more stars, but how this multiplicity arises is not clear and so far there have been no unequivocal observations of protostellar systems that could solve the issue. Now, systems of five, four and three stars, and several binaries, have been resolved in a star-forming region, and point to core fragmentation as the likely origin of multiplicity.

Although both are rocky planets in the habitable zone, Venus and Earth followed different climate evolutionary paths. This Perspective argues for the importance of Venus for understanding planetary habitability and terrestrial planet evolution.

Cosmic rays at petaelectronvolt energies permeate the Milky Way, but their origin is unknown. This Review Article summarizes the physics required to accelerate particles to these ultrahigh energies, and their potential astrophysical sources (‘PeVatrons’).

This Article provides evidence for apatite in a ferroan anorthosite clast in a lunar meteorite, allowing direct measurement of the volatile systematics of the primary products of the lunar magma ocean and the earliest lunar crust.

Numerical simulations of the DART impact on asteroid Didymos’s moon Dimorphos highlight its rubble-pile nature with a low bulk density and boulder volume fraction. These results indicate that Dimorphos formed from reaccumulated material shed from Didymos via rotation or impact.

The Eridania region of Mars bears various topographic and geomorphologic signatures of extensive volcanotectonic episodes and diverse volcanism that happened 3.5–4 billion years ago, indicative of vertical crustal recycling similar to Archaean Earth.

A prominent under-density in the observed radius distribution separates small exoplanets in two categories. The study demonstrates, through planet formation and evolution simulations, that the larger planets, whose composition has been disputed, may be water-rich planets migrating towards the star, where they become steam worlds.

High spatial resolution ALMA observations reveal a group of gravitationally bound quintuple, quadruple, triple and binary protostellar systems in the early stages of formation in a high-mass protocluster. This finding provides a direct measurement of the multiplicity of high-mass star formation.

While turbulent dissipation is prevalent in astrophysics, the processes that convert turbulent energy into heat are often unclear. This study shows that plasma waves are fundamental to heating the solar wind and similar turbulent astrophysical systems.

A very uncommon detached binary system with a 20.5-min orbital period has been discovered to harbour a carbon–oxygen white dwarf star and a low-mass subdwarf B star with a seven-Earth radius that traces the theoretical limit of binary evolution predicted 20 years ago.

By day 1,041 after explosion, SN Ia-CSM 2018evt had produced an estimated 0.01 solar masses of dust in the cold, dense shell behind the supernova ejecta–circumstellar medium interaction, ranking it as one of the most prolific dust-producing supernovae ever recorded.

A black hole at the centre of a quasar at a redshift of z = 4 is accreting the mass of the Sun every day. The quasar’s extreme luminosity is equivalent to 50,000 times that of the Milky Way. Its broad-line region should be resolvable observationally and will provide an important test for broad-line region size–luminosity relationships.

High-energy radiation originating in the wind termination shock of young star clusters has been observed, without contamination from other sources such as supernovae. This adds the winds of star clusters to the list of cosmic-ray accelerators within the Galaxy.

A comparison of observations and simulations of satellite galaxies around massive galaxy groups reveals significant differences, including correlated motions of pairs of satellite galaxies, which challenge the standard model of cosmology.