Related papers: A primordial atmospheric origin of hydrospheric de…
A recent study by Ramirez et al. (2014) demonstrated that an atmosphere with 1.3-4 bar of CO2 and H2O, in addition to 5-20% H2, could have raised the mean annual and global surface temperature of early Mars above the freezing point of…
Regolith on Mars exchanges water with the atmosphere on a diurnal basis and this process causes significant variation in the abundance of water vapor at the surface. While previous studies of regolith-atmosphere exchange focus on the…
Remote sensing data from orbiter missions have proposed that ground ice may currently exist on Mars, although the volume is still uncertain. Recent analyses of Martian meteorites have suggested that the water reservoirs have at least three…
Hydrogen in rocky planet atmospheres has been invoked in arguments for extending the habitable zone via N2-H2 and CO2-H2 greenhouse warming, and providing atmospheric conditions suitable for efficient production of prebiotic molecules. On…
The existence of liquid water within an oxidized environment on early Mars has been inferred by the Mn-rich rocks found during recent explorations on Mars. The oxidized atmosphere implied by the Mn-rich rocks would basically be comprised of…
Water reservoirs in the Solar System exhibit a deuterium enrichment that links back to the physical environment at the time of stellar birth. Gas-phase and ice-grain deuterium enrichments occur through chemical processes that operate at low…
It is not yet entirely clear whether Mars began as a warm and wet planet that evolved towards the present-day cold and dry body or if it always was cold and dry with just some sporadic episodes of liquid water on its surface. An important…
The Moon-forming giant impact extensively melts and partially vaporizes the silicate Earth and delivers a substantial mass of metal to Earth's core. Subsequent evolution of the magma ocean and overlying atmosphere has been described by…
The ratio of nitrogen isotopes in the Martian atmosphere is a key constraint on the planet's atmospheric evolution. However, enrichment of the heavy isotope expected due to atmospheric loss from sputtering and photochemical processes is…
The presence of valleys on ancient terrains of Mars suggest that liquid water flowed on the martian surface 3.8 billion years ago or before. The above-freezing temperatures required to explain valley formation could have been transient, in…
Reconciling the geology of Mars with models of atmospheric evolution remains a major challenge. Martian geology is characterized by past evidence for episodic surface liquid water, and geochemistry indicating a slow and intermittent…
The evolution and escape of the martian atmosphere and the planet's water inventory can be separated into an early and late evolutionary epoch. The first epoch started from the planet's origin and lasted $\sim$500 Myr. Because of the high…
Observations show that the global deuterium-to-hydrogen ratio (D/H) in the local interstellar medium (ISM) is about 90% of the primordial ratio predicted by big bang nucleosynthesis. The high (D/H)$_{ISM}$ implies that only a small fraction…
Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues about their original formation environment. The organic materials in primitive solar system bodies have generally higher D/H ratios and show greater D/H variation…
Recent detection of exoplanets with Earth-like insolation attracts growing interest in how common Earth-like aqua planets are beyond the solar system. While terrestrial planets are often assumed to capture icy or water-rich planetesimals, a…
The relative abundance of deuterium and hydrogen is a potent tracer of planet formation and evolution. Jupiter and Saturn have protosolar atmospheric D/H ratios, a relic of substantial gas accretion from the nebula, while the atmospheres of…
Present-day Mars is cold and dry, but mineralogical and morphological evidence shows that liquid-water existed on the surface of ancient Mars. In order to explain this evidence and assess ancient Mars's habitability, one must understand the…
The origin of Earth oceans is controversial. Earth could have acquired its water either from hydrated silicates (wet Earth scenario) or from comets (dry Earth scenario). [HDO]/[H2O] ratios are used to discriminate between the scenarios.…
CO2+H2 greenhouse warming has recently emerged as a promising scenario to sufficiently warm the early martian surface to allow the formation of valley networks and lakes. Here we present numerical 3-D global climate simulations of the early…
Planetary embryos form protoplanets via mutual collisions, which can lead to the development of magma oceans. During their solidification, large amounts of the mantles' volatile contents may be outgassed. The resulting H$_2$O/CO$_2$…