相关论文: Modeling a Transient Secondary Paleo-Lunar Atmosph…

On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global climate simulations…

The origin, distribution, depth and volume of lunar volatiles remain open questions. One of the possible sources of Moon's volatiles is their volcanic outgassing during the peak of lunar volcanic activity ~3.5 Ga. This same outgassing would…

Early in the Moon's history volcanic outgassing may have produced a periodic millibar level atmosphere (Needham and Kring, 2017). We examined the relevant atmospheric escape processes and lifetime of such an atmosphere. Thermal escape rates…

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…

We discuss 3D global simulations of the early Martian climate that we have performed assuming a faint young Sun and denser CO2 atmosphere. We include a self-consistent representation of the water cycle, with atmosphere-surface interactions,…

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…

Mars has a thin (6 mbar) CO2 atmosphere currently. There is strong evidence for paleolakes and rivers formed by warm climates on Mars, including after 3.5 billion years (Ga) ago, which indicates that a CO2 atmosphere thick enough to permit…

Volatile elements - those that vaporize at low temperatures - are depleted in lunar rocks relative to terrestrial rocks. This systematic chemical depletion is evidence for vaporization and preferential removal of vapor from proto-lunar…

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…

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…

Mars today has no active volcanism and its atmosphere is oxidizing, dominated by the photochemistry of CO2 and H2O. Using a one-dimensional photochemical model, we consider whether plausible volcanic gas fluxes could have switched the…

The debate over the early Martian climate is among the most intriguing in planetary science. Although the geologic evidence generally supports a warmer and wetter climate, climate models have had difficulty simulating such a scenario,…

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…

Venus's past climate evolution is uncertain. General circulation model simulations permit a habitable climate as late as ~0.7 Ga, and there is suggestive-albeit inconclusive-evidence for previous liquid water from surface geomorphology and…

Prevailing models for the formation of the Moon invoke a giant impact between a planetary embryo and the proto-Earth \citep{Canup_2004, Cuk_Stewart_2012}. Despite similarities in the isotopic and chemical abundances of refractory elements…

Mars was characterized by cataclysmic groundwater-sourced surface flooding that formed large outflow channels and that may have altered the climate for extensive periods during the Hesperian era. In particular, it has been speculated that…

The climate of Mars likely evolved from a warmer, wetter early state to the cold, arid current state. However, no solutions for this evolution have previously been found to satisfy the observed geological features and isotopic measurements…

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…

Present-day Venus is an inhospitable place with surface temperatures approaching 750K and an atmosphere over 90 times as thick as present day Earth's. Billions of years ago the picture may have been very different. We have created a suite…

We create the first quantitative model for the early lunar atmosphere, coupled with a magma ocean crystallization model. Immediately after formation, the moon's surface was subject to a radiative environment that included contributions from…