Articles

Solar wind is highly structured yet variable. Close-up observations of the solar atmosphere reveal that the changing connectivity of multiple sources in the solar corona drives the observed complexity and variability in the inner heliosphere.

Observation of new lava flows between different Magellan radar scans in regions of Sif Mons and Niobe Planitia confirms that volcanism on Venus is still ongoing. This evidence also suggests the planet’s volcanic activity exceeds previous estimates.

The near-infrared spectrometer onboard JWST has detected CO₂ and CO ices on 56 and 29 trans-Neptunian objects, respectively, indicating two dominant compositional types among them. These compositional differences suggest varied formation regions in the protoplanetary disk.

Utilizing a synergistic dataset from three Mars orbiters, it is shown that water photolysis above the main region of cloud formation in the Martian atmosphere is the dominant source of hydrogen available for atmospheric escape on Mars.

Simulations show that the competing effects of the solar wind and planetary rotation can explain the structure of planetary aurorae: the former dominates for Earth-type and the latter for Jupiter-type aurorae, with the highly variable aurorae at Saturn representing a transition state.

The SPECULOOS project detected an Earth-sized planet in a short orbit around a nearby Jupiter-sized star. This planet, SPECULOOS-3 b, is one of the most promising rocky exoplanets for detailed emission spectroscopy characterization with JWST.

Precise mass and radius measurements of giant planet WASP-193 b find an extremely low density of 0.059 ± 0.014 g cm⁻³. Current evolutionary models cannot fully explain such a low density, but the extended atmosphere makes WASP-193 b very suitable for high-precision characterization via JWST.

A pathway towards the formation of pyridine and (iso)quinoline, precursors to DNA and RNA, is revealed for conditions appropriate to Saturn’s moon Titan and the Taurus molecular cloud, providing insight into the synthesis of prebiotic molecules in space.

V1298 Tau b is a 20–30-Myr-old Jovian-sized planet with a haze-free, metal-poor atmosphere and a potentially hot interior. These properties suggest that V1298 Tau b formed in situ via pebble accretion and that it is still evolving and likely to become a Neptune- or sub-Neptune-sized planet.

An updated Jeans parameter that includes tidal forces can distinguish the various driving forces, both exogenous and endogenous, of atmospheric escape from low-mass close-in exoplanets. Depending on its value, escape can be dominated by tidal forces, extreme ultraviolet stellar radiation or a combination of the two.

Decametre radio observations are challenging due to the presence of the ionosphere. Here Groeneveld et al. present a strategy to correct for the ionosphere that allows them to make sharp decametre radio images from the ground with the LOFAR telescope.

Phase-resolved mid-infrared observations from JWST of the hot gas giant WASP-43b detect a day–night difference of 659 ± 19 K. Comparison with climate models shows that the observations are compatible with cloudy skies, at least on the nightside, and the lack of methane detection suggests the presence of disequilibrium chemistry.

Cassini tracking data yield a lower Love number for Titan than previous analysis. This result is compatible with a low-density internal ocean that might consist of a mix of water and ammonia.

In situ observations reveal explosive mass ejections due to magnetic reconnection in the ionosphere of Mars, with a density cavity as direct evidence. Reconnection between strong open crustal fields can rapidly eject a large amount of mass from Mars.

A three-dimensional reconstruction of a bright flare orbiting the black hole Sagittarius A^* is computationally recovered from ALMA light curve data by constraining a neural network with a gravitational model of black holes.

Simulated close encounters between planetary systems and other stars reveal that outer giant planets on wide orbits tend to be ejected, with a fraction of them forming bound pairs. This scenario would lead to a population of free-floating binary planets in dense stellar environments

The Earth co-orbital asteroid Kamo‘oalewa, which is a target of the Chinese Tianwen-2 mission, may have a lunar origin instead of an asteroidal one. Dynamical constraints from numerical simulations suggest that it could be an escaping fragment from the lunar Giordano Bruno crater.

Foreign material delivered as a giant impact can dominate large portions of icy dwarf planets, according to impact simulations. This scenario may explain the peculiar shape and location of the Sputnik Planitia region on Pluto, without the need for a present-day subsurface ocean.

Analysis of high-resolution observations of solar ‘plage’ regions (areas of high magnetic field) shows a correlation between coronal emission and the thermodynamic properties of the chromosphere below. Simulations suggest the same heating source.

Stellar winds of main-sequence stars are extremely important for the evolution of both stars and planets, yet they are challenging to detect. Here a detection of charge-exchange X-ray emission from stellar winds from three main-sequence stars is presented, along with derived mass-loss rates.