The composition of the volcanic gas supplied to Venus’s atmosphere indicates that the planet has a dry interior and is unlikely to have condensed liquid water on its surface, substantially constraining its potential habitability.

Low atmospheric temperatures during the Martian aphelion freeze water ice in the troposphere which is then cold trapped and unable to transit up into the mesosphere, according to a radiative transfer model and cloud microphysics simulations

The connection between Mars’s global magnetospheric current systems and its ionosphere is still not well-defined. Here, the authors show a map of the magnetic fields and ionospheric currents of Mars, revealing two ionospheric currents that are driven by the solar wind and atmospheric neutral winds.

Aqueous alteration followed by dehydration and dispersion into Jezero crater is indicated by the identification of kaolinite or halloysite, spinel and a dehydrated Al-rich phase in spectroscopic observations of light-toned float rocks by the Perseverance rover

Mapping of the distances of secondary craters from their primary crater on the Moon, Mars, and Mercury indicates a unified power law relationship, regardless of gravity and target properties and suggests the minimum impact velocity is lower than expected.

Four years ago the Japan Aerospace Exploration Agency's Hayabusa2 mission returned samples of an asteroid to Earth. The latest results in the analysis of the sample material are presented in this issue of Nature Astronomy.

Humans first reached Mars in 1971, initiating the record of human activity on the Red Planet. As planetary scientists plan for future planetary protection procedures for Mars, they should also consider the developing archaeological record on one of our nearest planets.

The sample numbers required to achieve a 95% confidence, with high precision, that Martian environments are lifeless can exceed many hundreds. This might not be achievable by sample return only and might require human explorers.

The composition of Venus’s atmosphere is well known, and is likely being replenished by volcanic gases. Analysis suggests that the volcanic eruptions are water-poor — implying that the planet’s mantle is dry. This is consistent with Venus having had a long-lasting dry surface and never having been habitable.

Is Mars exploration stalling? The unused 2022 and 2024 launch windows send some warning signs. A revitalized approach could orient a new phase of exploration and complement the long-awaited sample return process.

In hyperarid environments, life can obtain water through salts that draw moisture from the atmosphere. These salts, then, should be a focus of searches for life on Mars. The experiments performed by NASA’s Viking landers may have accidentally killed Martian life by applying too much water.