Articles

A comprehensive study of the Kepler-138 system reveals the twin nature of Kepler-138 c and d and the presence of a fourth planet. Remarkably, the warm-temperate planet Kepler-138 d is probably composed of 50% volatiles by volume, indicative of a water world, rather than a rocky world, despite its small ~1.5 R_⊕ size.

A comparison of copper and zinc isotopic measurements between the Ryugu samples and various carbonaceous chondrites excludes any genetic link between the two except for the CI (Ivuna-type) chondrites. Ryugu-like material might have accounted for ~5% of Earth’s mass.

Observations of a meteoroid coming from the Oort cloud show that it is made of rocky and not icy material, constraining the ratio of rocky to icy objects impacting Earth from the Oort cloud to \({6}_{-5}^{+13}\)%.

A multi-observational study including laboratory analysis of the Chang’e-5 mission samples, in situ measurements and orbital datasets determined the high level of maturity and iron content of the Chang’e-5 landing site regolith. Heavily processed by space weathering, it mostly comes from the nearby Xu Guangqi crater, formed 240–300 Myr ago.

An ultraviolet- and carbon-rich environment is needed to explain the bright emission coming from complex organic molecules observed near the midplane of protoplanetary disks. This implies that the gaseous reservoir from which actively forming planets accrete is carbon and organic rich.

Measurements of the Rossiter–McLaughlin effect for the ultra-short-period super-Earth 55 Cancri e reveal a signal with a semi-amplitude of 0.41+0.09-0.10 m s⁻¹, in close alignment with its star and potentially misaligned with the other planets in the system. Such a configuration favours a non-violent migration pathway for 55 Cnc e.

Simultaneous polarimetry measurements in the optical and radio bands for the afterglow emission of GRB 191221B provide insights into particle acceleration and total energy budget of gamma-ray bursts.

JWST observations of the planetary nebula NGC 3132 reveal a rich molecular environment containing evidence of multiple stellar interactions on a variety of scales.

Early emission from gamma-ray burst GRB 211211A comes entirely from charged particles accelerating in strong magnetic fields. The fast-evolving spectrum may be the key to understanding unusually long-lived GRBs from neutron star mergers.

Quantum sensors, such as atomic clocks, placed deep into the inner Solar system, may be sufficiently sensitive to directly detect ultralight dark matter bound by the mass of the Sun.

An ~4,000-km-diameter and 200–500-km-thick active mantle plume is present below Elysium Planitia on Mars, indicating that the Martian interior is geodynamically active and drives the volcanic and seismic activity of the region. Studies from the InSight lander need to consider the presence of the plume.

By modelling the radio, optical, UV and X-ray data of the unusually bright cosmological explosion AT 2022cmc, Pasham et al. argue for the presence of a highly collimated jet moving at ≳99.99% the speed of light.

An analysis of several models provides astrophysical constraints on the Universe at redshift ~20, corresponding to ~200 million years after the Big Bang, using upper limits on the sky-averaged 21-cm signal measured by the SARAS 3 radiometer.

Individual productivity among astronomers was boosted during the COVID-19 pandemic, but the improvement was not shared equally between men and women: a smaller fraction of papers were written by female astronomers and fewer women were among incoming new researchers in many countries.

Using detailed solar coronal observations and advanced magnetohydrodynamics simulations, the authors find that a coronal web above a region of coronal holes and active regions dynamically evolves and persistently drives the highly structured slow solar wind.

Exoplanets with radii between 1.4 and 2.5 R_⊕ may have atmospheres strongly enhanced in helium after a few billion years, due to the preferential loss of hydrogen over helium via photoevaporation. If observed, this phenomenon could demonstrate the importance of photoevaporation in shaping the radius valley.

Observational evidence from planetary systems around white dwarfs shows that planetesimal formation occurs during the first few hundred thousand years after cloud collapse. Iron accreted by these white dwarfs must have been formed by short-lived radioactive nuclides driving iron core formation in planetesimals that form together with the parent star.

Solar wind observations from the Magnetospheric Multiscale mission reveal bursty, turbulent properties within a reconnection diffusion region, in contrast with the usual quasi-steady state of solar wind reconnection. Between October 2017 and May 2019 75 other similar events were identified, indicating the relevance of turbulent reconnection in the solar wind.

The rapid rise in brightness of a tidal disruption event is attributed to the destruction of a main sequence star by a black hole of intermediate mass in a dwarf galaxy. Such events are rare, and non-accreting intermediate-mass black holes are challenging to find.

Spectroscopic and photometric analyses show the B-type-star γ Columbae to be the exposed stellar core of a massive progenitor star that has just finished central hydrogen fusion.