Related papers: Transient reducing greenhouse warming on early Mar…

We propose a mechanism for the oxidation of gaseous CO into CO2 occurring on the surface mineral hematite (Fe2O3(s)) in hot, CO2-rich planetary atmospheres, such as Venus. This mechanism is likely to constitute an important source of…

Exoplanets with lower equilibrium temperatures than Earth and primordial hydrogen atmospheres that evaporate after formation should pass through transient periods where oceans can form on their surfaces, as liquid water can form below a few…

We investigate the global seasonal variations of near-surface relative humidity and relevant attributes, like temperature and water vapor volume mixing ratio on Mars using calculations from modelled and measurement data. We focus on 2 am…

Young terrestrial planets can capture or outgas hydrogen-rich atmospheres with tens to hundreds of bars of H2, which persist for 100 Myrs or longer. Although the earliest habitable conditions on Earth and terrestrial exoplanets could thus…

The habitable zone (HZ) is the circumstellar region where standing bodies of liquid water could exist on the surface of a rocky planet. Conventional definitions assume that CO2 and H2O are the only greenhouse gases. The outer edge of this…

Earth is expected to have acquired a reduced proto-atmosphere enriched in H2 and CH4 through the accretion of building blocks that contain metallic Fe and/or the gravitational trapping of surrounding nebula gas. Such an early, wet, reduced…

Many parameters constraining the spectral appearance of exoplanets are still poorly understood. We therefore study the properties of irradiated exoplanet atmospheres over a wide parameter range including metallicity, C/O ratio and host…

Characterizing the exchange of water between the Martian atmosphere and the (sub)surface is a major challenge for understanding the mechanisms that regulate the water cycle. Here we present a new dataset of water ice detected on the Martian…

We used chemical equilibrium and chemical kinetic calculations to model chemistry of the volatiles released by heating different types of carbonaceous, ordinary and enstatite chondritic material as a function of temperature and pressure.…

The illuminated dusty surface of Mars acts like a gas pump. It is driven by thermal creep at low pressure within the soil. In the top soil layer this gas flow has to be sustained by a pressure gradient. This is equivalent to a lifting force…

Whether extant life exists in the martian subsurface is an open question. High concentrations of photochemically produced CO and H2 in the otherwise oxidizing martian atmosphere represent untapped sources of biologically useful free energy.…

Channel networks on the plateau adjacent to Juventae Chasma have the highest drainage densities reported on Mars.We model frozen precipitation on the Juventae plateau,finding that the trigger for forming these channel networks could have…

In this work we present laboratory measurements on the reduction of the threshold friction velocity necessary for lifting dust if the dust bed is illuminated. Insolation of a porous soil establishes a temperature gradient. At low ambient…

Cold super-Earths which retain their primordial, H-He dominated atmosphere could have surfaces that are warm enough to host liquid water. This would be due to the collision induced absorption (CIA) of infra-red light by hydrogen, which…

The climate on early Mars is one of the major unsolved problems. It is unclear whether early Mars was warm and wet or cold and icy. Morphological features on Mars such as sinuous ridges could provide critical constraints to address this…

A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface…

We consider super-Earth sized planets which have a water mass fraction that is large enough to form an external mantle composed of high pressure water ice polymorphs and that lack a substantial H/He atmosphere. We consider such planets in…

Using a 3D General Circulation Model, the Unified Model, we present results from simulations of a tidally-locked TRAPPIST-1e with varying carbon dioxide CO2 and methane CH4 gas concentrations, and their corresponding prescribed spherical…

In 2020, hydrogen chloride (HCl) in the gas phase was discovered in the atmosphere of Mars with the Atmospheric Chemistry Suite (ACS) onboard the Trace Gas Orbiter (TGO) mission (Korablev et al., 2021). Its volume mixing ratio (VMR) shows a…

We use a 3D general circulation model to compare the primitive Martian hydrological cycle in "warm and wet" and "cold and icy" scenarios. In the warm and wet scenario, an anomalously high solar flux or intense greenhouse warming…