Reviews & Analysis

JWST observations of WASP-107 b reveal extended pre-transit and post-transit helium absorption, suggesting the planet has a giant escaping atmosphere. The results provide fresh insight into the planet’s inflated envelope, mass loss and migratory past, and demonstrate the power of long-baseline transit spectroscopy for tracing exoplanet evolution.

When icy ocean worlds in the outer Solar System experience episodes of heating, their ice shells thin. Modelling shows that this thinning can lead to boiling of the ocean beneath the ice shell, or to compressional faulting — and that the outcome is determined by the size of the moon.

Einstein’s theory of general relativity includes black holes but so do other theories of gravity, and the predictions are not sufficiently different to decide whether the supermassive black holes imaged so far, by the Event Horizon Telescope, really match Einstein’s prediction. But advanced simulations demonstrate that next-generation telescopes will achieve the precision needed to distinguish black holes in different theories and probe fundamental physics near the event horizon.

Coordinated observations between the Hubble Space Telescope and ground-based telescopes of a star that is an analogue of the young Sun have uncovered multi-temperature signatures of stellar coronal mass ejections. The detection of fast–warm and slow–cool plasma components suggests a solar-like but more complex picture of stellar eruptions, with impact on the planets around young stars.

By generating natural-language explanations alongside accurate classifications, large language models offer a new way to filter astronomical alerts — bridging the gap between fast automation and human understanding.

JWST has spatially resolved ro-vibrational CO emission excited by fluorescence in the 49 Ceti debris disk. These observations provide insight into the nature and origin of gas in debris disks.

A coherent 909-Hz quasi-periodic oscillation (QPO) has been detected, briefly, in the second brightest gamma-ray burst recorded to date, GRB 230307A. This burst originated from a merger of compact stars, and the QPO signal implies the presence of a millisecond magnetar, formed after the merger.

Intriguing signals have been detected by the Perseverance rover from the floor and fan top of the Jezero crater on Mars. Laboratory investigations provide insight into the origin of these signals, identifying aromatic organic molecules — polycyclic aromatic hydrocarbons — preserved in sulfates.

Morphology and dynamics probe early galaxy formation. Contrary to previous understanding that early galaxies comprise smooth structures, high-resolution observations combined with gravitational lensing reveal at least 15 star-forming clumps within a rotating galaxy from 900 million years after the Big Bang. These observations challenge current theories of early galaxy formation.

A spatially resolved JWST study of a quiescent massive galaxy and its neighbourhood at a high redshift reveals that just 1.6 Gyr after the Big Bang, the galaxy had formed \(\,{10}^{11}{M}_{\odot }\) in stars and was surrounded by an abundant gas reservoir. Nevertheless, following early cessation of star formation, the galaxy remained quenched for more than 500 Myr.

Identifying viable impact scenarios that can reproduce the internal structure of Mercury, which is mainly composed of an iron core, is a long-standing problem. Hydrodynamic simulations show that collisions between two growing planets with comparable masses and appropriate speed and angle configurations could form Mercury’s unique structure.

A giant exoplanet has been discovered transiting a star with a mass just 20% of that of the Sun. This exoplanetary system poses a challenge to the current understanding of how giant planets form.

Simulations show how the orbits of planets gravitationally scattered outward might be perturbed by passing stars within the star’s birth cluster, leading to the planets becoming stranded on wide orbits — such as hypothetical Planet Nine. These results lead to the prediction of a rich population of very-wide-orbit planets in the Galaxy.

A galactic nucleus began emitting X-rays, periodically, in 2024. These quasi-periodic eruptions have the highest fluxes and longest timescales of any detected so far, and are thought to originate from newly formed accretion flows onto a supermassive black hole.

An examination of nearly 8,000 impact observations indicates that the objects most likely to reach the Earth’s surface have experienced substantial thermal stress during close solar encounters. Around half of the remaining objects are then removed by the atmosphere, resulting in a filtered subset of material in the meteoritic collection.

The Andromeda galaxy is surrounded by a constellation of dwarf galaxies that are arranged in a highly lopsided manner. Analysis of cosmological simulations reveals that this degree of asymmetry is found in only 0.3% of similar systems, painting Andromeda as a striking outlier in the current cosmological paradigm.

A galaxy has been discovered at an early cosmic time — two billion years after the Big Bang — that has a giant disk, grown to a size more typical of the largest disks in the present Universe. The early and quick growth of this disk might be related to its special, over-dense environment.

State-of-the-art computer simulations show that the first water in the Universe formed in primordial supernova remnants 100 Myr after the Big Bang. This water enriched sites of future planet formation, leading to water mass fractions close to those present in the Solar System today.

Observations of polarized thermal emission from dust grains in the protoplanetary disk around the HD 142527 protostar suggest that in part of the disk the polarization is caused by the magnetic field. The strength and structure of this magnetic field are deduced from these observations using a modelling approach.

A suborbital experiment indicates that centimetre-sized clusters of tribocharged submillimetre grains resist erosion by individual grains with collision speeds up to around 0.5 m s^–1. The stability of these charged clusters allows them to grow larger than uncharged clusters, enabling the formation of planetesimals in protoplanetary disks.