Related papers: The Survival Rate of Ejected Terrestrial Planets w…
The leading theory for the formation of the Earth's moon invokes a collision between a Mars-sized body and the proto-Earth to produce a disk of orbiting material that later condenses to form the Moon. Here we study the early evolution of…
The existence of giant planets on wide orbits ($\stackrel{>}{_\sim}100$AU) challenge planet formation theories; the core accretion scenario has difficulty in forming them, whereas the disc instability model forms an overabundance of them…
Warm giant planets with orbital periods of tens of days exhibit a positive correlation between mass and eccentricity. We interpret this trend as the outcome of planet-planet scattering, representing a transition from collision-dominated…
We have now accumulated a wealth of observations of the planet-formation environment and of mature planetary systems. These data allow us to test and refine theories of gas-giant planet formation by placing constraints on the conditions and…
We present models for the formation of terrestrial planets, and the collisional evolution of debris disks, in planetary systems that contain multiple unstable gas giants. We previously showed that the dynamics of the giant planets…
In the nucleated instability picture of gas giant formation, the final stage is the rapid accretion of a massive gas envelope by a solid core, bringing about a tenfold or more increase in mass. This tends to trigger the scattering of any…
Characterizing habitable exoplanets and/or their moons is of paramount importance. Here we show the results of our magnetic field topological modeling which demonstrate that terrestrial exoplanet-exomoon coupled magnetospheres work together…
Recent discoveries of extrasolar planets at small orbital radii, or with significant eccentricities, indicate that interactions between massive planets and the disks of gas and dust from which they formed are vital for determining the final…
Short-period Earth to Neptune size exoplanets (super-Earths) with voluminous gas envelopes seem to be very common. These gas atmospheres are thought to have originated from the protoplanetary disk in which the planets were embedded during…
The distribution of exoplanet masses is not primordial. After the initial stage of planet formation is complete, the gravitational interactions between planets can lead to the physical collision of two planets, or the ejection of one or…
Gravitational torques between a planet and gas in the protoplanetary disk result in orbital migration of the planet, and are likely to play an important role in the formation and early evolution of planetary systems. For masses comparable…
The high occurrence rates of spiral arms and large central clearings in protoplanetary disks, if interpreted as signposts of giant planets, indicate that gas giants form commonly as companions to young stars ($<$ few Myr) at orbital…
Terrestrial planets are thought to be the result of a vast number of gravitational interactions and collisions between smaller bodies. We use numerical simulations to show that practically identical initial conditions result in a wide array…
Satellite formation is a natural by-product of planet formation. With the discovery of nu- merous extrasolar planets, it is likely that moons of extrasolar planets (exomoons) will soon be discovered. Some of the most promising techniques…
To date, two planetary systems have been discovered with close-in, terrestrial-mass planets (< 5-10 Earth masses). Many more such discoveries are anticipated in the coming years with radial velocity and transit searches. Here we investigate…
The origin of close-in giant planets is a key open question in planet formation theory. The two leading models are (i) formation at the outer disk followed by migration and (ii) in situ formation. In this work we determine the atmospheric…
Recent observational findings have suggested a positive correlation between the occurrence rates of inner super-Earths and outer giant planets. These results raise the question of whether this trend can be reproduced and explained by planet…
The Moon is believed to have formed in the aftermath of a giant impact between a planetary mass body and the proto-Earth. In a typical giant impact scenario, a disk of vapor, liquid, and solid debris forms around the proto-Earth and--after…
Models of terrestrial planet formation for our solar system have been successful in producing planets with masses and orbits similar to those of Venus and Earth. However, these models have generally failed to produce Mars-sized objects…
M type stars are good targets in the search for habitable extrasolar planets. Because of their low effective temperatures, the habitable zone of M stars is very close to the star itself. For planets close to their stars, tidal heating plays…