Related papers: Warming early Mars with CO2 and H2
We use a hierarchy of numerical models (a 3-D Global Climate Model, a 1-D radiative-convective model and a 2-D Mantle Dynamics model) to explore the environmental effects of very large impacts on the atmosphere, surface and interior of…
Recent findings suggest Mars may have been a clement environment for the emergence of life, and may even have compared favorably to Earth in this regard. These findings have revived interest in the hypothesis that prebiotically important…
Despite decades of scientific research on the subject, the climate of the first 1.5 Gyr of Mars history has not been fully understood yet. Especially challenging is the need to reconcile the presence of liquid water for extended periods of…
The low temperatures and high ultraviolet (UV) radiation levels at the surface of Mars today currently preclude the survival of life anywhere except perhaps in limited subsurface niches. Several ideas for making the martian surface more…
Two arguments have suggested the presence of subsurface water ice at latitudes lower than 30\textdegree~on Mars. First, the absence of CO2 frost on pole-facing slopes was explained by the presence of subsurface ice. Second, models suggested…
The impact heat accumulated during the late stage of planetary accretion can melt a significant part or even the entire mantle of a terrestrial body, giving rise to a global magma ocean. [...] Assuming fractional crystallization of the…
Water photolysis and hydrogen loss from the upper atmospheres of terrestrial planets is of fundamental importance to climate evolution but remains poorly understood in general. Here we present a range of calculations we performed to study…
The abundance of highly siderophile elements (HSEs) inferred for Mars' mantle from martian meteorites implies a Late Veneer (LV) mass addition of ~0.8 wt% with broadly chondritic composition. Late accretion to Mars by a differentiated…
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…
Recent observations have evidenced traces of methane CH4 heterogeneously distributed in the martian atmosphere. However, because the lifetime of CH4 in the atmosphere of Mars is estimated to be around 300-600 years on the basis of…
The gullies on Mars were discovered in the year 1999.Since then several hypotheses have appeared trying to explain the presence of these gullies. The main hypotheses are the ones which suggest that some liquid, water or CO2, was responsible…
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…
The history of rivers on Mars is an important constraint on Martian climate evolution. The timing of relatively young, alluvial fan-forming rivers is especially important, as Mars' Amazonian atmosphere is thought to have been too thin to…
Mars finished forming while the solar nebula was still present, and acquired its primordial atmosphere from this reservoir. The absence of a detectable cometary xenon signature in the present-day Martian atmosphere suggests that the capture…
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…
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.…
Mars is believed to have had a substantial atmosphere in the past. Atmospheric loss led to depressurization and cooling, and is thought to be the primary driving force responsible for the loss of liquid water from its surface. Recently,…
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…
The frequently discovered flooding structure on Mars and other planets has long been an intriguing mystery remained un-disclosed so far. Considering that on Earth, quite a few low melting point liquid metals or their alloy can be candidates…
After Earth's origin, our host star, the Sun, was shining 20 to 25 percent less brightly than today. Without greenhouse-like conditions to warm the atmosphere, our early planet would have been an ice ball and life may never have evolved.…