Related papers: Building Wet Planets through High-Pressure Magma-H…
The temperature and density profiles of protoplanetary discs depend crucially on the mass fraction of micrometre-sized dust grains and on their chemical composition. A larger abundance of micrometre-sized grains leads to an overall heating…
Recent observations found close-in planets with significant atmospheres of hydrogen and helium in great abundance. These are the so-called super-Earths and mini-Neptunes. Their atmospheric composition suggests that they formed early during…
During the formation of rocky planets, the surface environments of growing protoplanets were dramatically different from those of present-day planets. The release of gravitational energy during accretion would have maintained a molten…
Planets with masses between Earth and Neptune often have radii that imply the presence of volatiles, suggesting that water may be abundant in their interiors. However, directly observing the precise water mass fraction and water…
Many exoplanets have been discovered with radii of 1-4 Earth radii, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are "sub-Neptunes" likely to have…
To understand the role that planet formation history has on the observable atmospheric carbon-to-oxygen ratio (C/O) we have produced a population of astrochemically evolving protoplanetary disks. Based on the parameters used in a…
Kepler has found hundreds of Neptune-size (2-6 R_Earth) planet candidates within 0.5 AU of their stars. The nature of the vast majority of these planets is not known because their masses have not been measured. Using theoretical models of…
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…
Observations of temperate sub-Neptunes suggest active chemical environments, finding evidence of both water vapor and photochemical hazes in their atmospheres. Hazes formed in water-rich atmospheres are chemically complex, containing…
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 discovery of thousands of highly irradiated, low-mass, exoplanets has led to the idea that atmospheric escape is an important process that can drive their evolution. Of particular interest is the inference from recent exoplanet…
A sufficient amount of water is required at the surface to develop water oceans. A significant fraction of water, however, remains in the mantle during magma ocean solidification, and thus the existence of water oceans is not guaranteed…
Some large trans-Neptunian objects could be formed by the compression of rarefied dust condensations, but not by the accumulation of smaller planetesimals. A considerable portion of near-Earth objects could have come from the…
The atmosphere of a terrestrial planet that is replenished with secondary gases should have accumulated hydrogen-rich gas from its protoplanetary disk. Although a giant impact blows off a large fraction of the primordial atmosphere of a…
We examine the possibility that icy super-Earth mass planets, formed over long time scales (0.1--1~Gyr) at large distances ($\sim$ 200--1000~AU) from their host stars, will develop massive H-rich atmospheres. Within the interior of these…
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…
Photo-evaporative mass loss sculpts the atmospheric evolution of tightly-orbiting sub-Neptune-mass exoplanets. To date, models of the mass loss from warm Neptunes have assumed that the atmospheric abundances remain constant throughout the…
Observed high multiplicity planetary systems are often tightly packed. Numerical studies indicate that such systems are susceptible to dynamical instabilities. Dynamical instabilities in close-in tightly packed systems, similar to those…
Recent observations have found a valley in the size distribution of close-in super-Earths that is interpreted as a signpost that close-in super-Earths are mostly rocky in composition. However, new models predict that planetesimals should…
Super-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior-atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including…