Articles in 2022

Out of more than 3,000 clasts contained in the Chang’e-5 lunar sample, 7 do not come from the region of the Chang’e-5 landing sites. These exotic clasts highlight the lithological diversity of the lunar crust, and their scarcity hints at the need for alternative models for impact ejecta onto young lunar terrains.

Oxygen isotopic measurements from the Ryugu returned sample suggest that primitive hydrated carbonaceous chondrites are an important source of early water and other volatiles to Earth, despite being underrepresented in our meteorite collection due to their preferential destruction during atmospheric entry.

Infrared observations of Jupiter obtained in a 40-yr timespan between 1978 and 2019 show long-term variations of Jupiter’s tropospheric temperature with different periodicities, particularly at tropical latitudes, which often bear some connection with stratospheric temperature fluctuations.

A close-up look at the action of space weathering on carbonaceous asteroids, provided by Ryugu’s returned samples, highlights its role on the dehydration of the first micrometre-thick layer of the surface, possibly hiding a water-rich interior. The depth of the 2.7 µm hydration band may be an indication of the level of space weathering withstood by a C-type asteroid.

Wind power can be an oft-neglected source of energy for future human exploration missions on Mars, especially coupled with solar power. Modelling shows that solar and wind energy can fully power such missions for more than half of the Martian year for ten regions of interest identified by NASA. Another 13 promising sites are identified.

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 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.

We are still in the early days of open science, with implementation lagging ideation. But the benefits are clear and progress is picking up.

The GHOST spectrograph will shortly be available on the Gemini South Telescope for studies of stellar and galactic abundances and, in time, exoplanets.

A vital part of future planetary science missions will be the development of more inclusive teams. As NASA’s InSight mission comes to its end on Mars, we share some strategies that have helped us to work toward this goal.

At a Lorentz Center workshop, Chiara Caprini, Antoine Petiteau and Elena Maria Rossi gave a series of presentations about the Laser Interferometer Space Antenna (LISA) mission, the instrument, and the associated science in cosmology and astrophysics.

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.

Upcoming X-ray microcalorimeter missions should deliver high spectral finesse, and allow detailed studies of accretion processes and feedback mechanisms in growing black holes.

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.