Related papers: Warming early Mars with CO2 and H2
Mars is the only planet, other than Earth, for which there are several evidences that liquid water was abundant at the surface. Among them, one of the best evidence is that the ancient terrains of Mars are covered with fluvial and…
Carbon dioxide (CO$_2$) ice clouds have been routinely observed in the middle atmosphere of Mars. However, there are still uncertainties concerning physical mechanisms that control their altitude, geographical, and seasonal distributions.…
The detection of geologically recent channels at the end of the twentieth century rapidly suggested that liquid water could have been present on Mars up to recent times. A mechanism involving melting of water ice during ice ages in the last…
We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas, and that bars or tens of bars of primordial H2-He mixtures can maintain surface temperatures above the freezing point of water…
The origin of life on Earth seems to demand a highly reduced early atmosphere, rich in CH4, H2, and NH3, but geological evidence suggests that Earth's mantle has always been relatively oxidized and its emissions dominated by CO2 H2O, and…
Massive steam and CO$_2$ atmospheres have been proposed for magma ocean outgassing of Earth and terrestrial planets. Yet formation of such atmospheres depends on volatile exchange with the molten interior, governed by volatile solubilities…
The detection of sulphur species in the Martian atmosphere would be a strong indicator of volcanic outgassing from the surface of Mars. We wish to establish the presence of SO2, H2S, or OCS in the Martian atmosphere or determine upper…
Surface release of radiatively active particles, with high infrared- (IR-)to-visible extinction ratios, has been proposed as a method of warming Mars. However, to warm Mars using aerosols, particles released locally must disperse globally.…
Atmospheric escape is an important process that influences the evolution of planetary atmospheres. A variety of physical mechanisms can contribute to escape from an atmosphere, including thermal escape, ion escape, photochemical escape, and…
The planetary differentiation models of Mars are proposed that take into account core-mantle and core-mantle-crust differentiation. The numerical simulations are presented for the early thermal evolution of Mars spanning up to the initial…
Several clues indicate that Titan's atmosphere has been depleted in methane during some period of its history, possibly as recently as 0.5-1 billion years ago. It could also happen in the future. Under these conditions, the atmosphere…
Ozone is an important radiative trace gas in the Earth's atmosphere. The presence of ozone can significantly influence the thermal structure of an atmosphere, and by this e.g. cloud formation. Photochemical studies suggest that ozone can…
Terraforming Mars can be evaluated with a set of system-level constraints linking (i) target pressures & compositions to required atmospheric inventories, (ii) target surface temperatures to the required radiative control, (iii) inventories…
In this Letter, we make use of sophisticated 3D numerical simulations to assess the extent of atmospheric ion and photochemical losses from Mars over time. We demonstrate that the atmospheric ion escape rates were significantly higher (by…
Geological evidence suggests liquid water near the Earth's surface as early as 4.4 billion years ago when the faint young Sun only radiated about 70% of its modern power output. At this point, the Earth should have been a global snowball if…
This roadmap outlines research pathways to determine whether Mars could be warmed with non-biological methods. It does not presuppose that warming Mars is desirable; its purpose is to identify what would need to be true for Mars to be…
Carbon dioxide ice clouds are thought to play an important role for cold terrestrial planets with thick CO2 dominated atmospheres. Various previous studies showed that a scattering greenhouse effect by carbon dioxide ice clouds could result…
It is currently uncertain as to whether methane exists on Mars. Data from the Curiosity Rover suggests a background methane concentration of a few tenths parts per billion whereas data from the Trace Gas Orbiter suggest an upper limit of…
Mars is the Solar System's canonical small, rocky planet that transitioned from early geologic activity and surface liquid water to a cold and arid planet with a thin, cold, CO$_2$-dominated atmosphere. The evolution of Mars, in the context…
Under a terraforming scenario, a reactivated hydrological cycle on Mars will result in upwards movement of water due to evaporation and precipitation. If Mars' embryonic fossilized catchments provide inadequate drainage, Mars' limited…