Wind, water and dust on Mars

Early Mars did not experience a single wet-to-dry transition, but seven such shifts in its palaeoclimatic history, as argued based on the planet’s stratigraphy, mineralogy and geomorphology.

Common ground between human spaceflight and astrobiology can be used as the foundation for a new deal in the exploration of Mars that will allow stakeholders to reach critical astrobiological goals while supporting safer human exploration.

Mars hosted hundreds of lakes, most of which formed earlier than 3.7 billion years ago and lasted only a limited amount of time. This overview of their characteristics and mineralogy highlights the importance of the Martian lakes as a record of ancient climate and potential for biogenesis.

The presence of iron-rich X-ray amorphous material on the Martian surface is consistent with in situ aqueous alteration indicative of cool and relatively wet conditions in the past, according to a comparison between material from various terrestrial soils and Gale crater

Mars, an attractive candidate for potential presence of extraterrestrial life, contains oxychlorine species such as perchlorate at its surface. Here, the authors show perchlorate brines support folding and catalysis of functional RNAs, while inactivating representative protein enzymes, and that perchlorate enables new ribozyme functions, including ribozyme catalyzed chlorination of organic molecules.

Microbial communities can be incubated and grown in sawdust from a martian meteorite under terrestrial conditions, which suggests that martian regolith could be used for cultivation in human habitats on Mars under the appropriate conditions.

Manganese oxidation experiments in Mars-like fluids suggest that chlorate and bromate may have been more effective oxidants of manganese on early Mars than atmospheric oxygen and explain observed manganese oxide deposits.

Sediments on the northern plains of Mars experienced aqueous alteration during interaction with a limited or ephemeral water source, according to spectral analyses of Martian rocks and soils encountered by the Zhurong rover.

Multiple climatic events on Mars over a large range of geologic time, which peaked 3.7–3.8 billion years ago may have created warm, wet and anoxic conditions episodically, according to a compilation of over 200 Martian chemical weathering profiles.

Laboratory experiments show that the type of iron mineral is the dominant factor controlling the chlorate/perchlorate (ClO₃⁻/ClO₄⁻) generation ratio on Mars over oxidation methods or atmospheric composition. Chlorate yields are found to exceed perchlorate yields by orders of magnitude in the current desiccated Martian conditions.

High perchlorate/chloride ratios at the Phoenix landing site in the Martian northern polar region could have formed by specific relative humidity and temperature conditions coupled with dust transport, according to experiments and thermodynamic modeling.

Terrestrial chemolithotrophic microbes living on Martian crustal material produce distinct biosignatures which could be detected by future missions searching for evidence of past life, according to experiments on a Noachian Martian meteorite.

Carbon dioxide gas sublimated from frost at locations of high temperature difference could mobilize surface sediments in gully features observed on the Martian surface, according to flume tank experiments and numerical climate modelling.

Spatial patterns of channel sinuosity near river outlets reflect the interplay between the channel migration rate and the avulsion timescale, according to sinuosity measurements of lowland rivers on Earth and Mars and channel evolution simulations.

Meteorology measurements from NASA’s Perseverance rover on Mars reveal a diversity of processes at work in the atmospheric boundary layer at Jezero crater over a range of temporal scales.

Dust devils are common on Mars and understanding their dynamics is important to gain insights about the meteorology of the planet. Here, the authors show characteristics of a Martian dust devil and its sound from Perseverance rover multi-sensor data combined with modelling.

Dust storms on Mars drive water escape to space. Here, the authors show the impact Martian dust storms have on the abundance of atmospheric hydrogen and oxygen, and how this helps to overall oxidize the Martian atmosphere.

Dust storms on Mars drive water escape to space. Here, the authors show the impact Martian dust storms have on the abundance of atmospheric hydrogen and oxygen, and how this helps to overall oxidize the Martian atmosphere.

Numerical simulations of the exhumation of basin-filling river deposits suggest that ridge networks observed in Martian landscapes may represent erosional windows into sedimentary basins on Mars.

Transverse aeolian ridges on Mars develop into networked configurations by formation of secondary ridges, reactivation of primary ridges and a transition from 3D to 2D air flow, according to analyses of HiRISE images from the Mars Reconnaissance Orbiter.

Observations by the Curiosity rover at Gale Crater on Mars indicate that high-frequency wet–dry cycling occurred on the early Martian surface, indicating a possible seasonal climate conducive to prebiotic evolution on early Mars.

Raman and fluorescence spectra, consistent with several species of aromatic organic molecules, are reported in the Crater Floor sequences of Jezero crater, Mars, suggesting multiple mechanisms of organic synthesis, transport, or preservation.

Evidence for a stratigraphic sequence involving initial barchan dune formation, with the transition in wind regime consistent with the end of the ice age is found, compatible with the Martian polar stratigraphic record.

Using data gathered from the microphones of the Perseverance rover, the first characterization of the acoustic environment on Mars is presented, showing two distinct values for the speed of sound in CO₂-dominated atmosphere.