Analytical Model for the Tidal Evolution of the Evection Resonance and the Timing of Resonance Escape.

A high-angular momentum giant impact with the Earth can produce a Moon with a silicate isotopic composition nearly identical to that of Earth's mantle, consistent with observations of terrestrial and lunar rocks. However, such an event requires subsequent angular momentum removal for consistency with the current Earth-Moon system. The early Moon may have been captured into the evection resonance, occurring when the lunar perigee precession period equals 1 year.

A compositionally heterogeneous martian mantle due to late accretion.

The approximately chondritic estimated relative abundances of highly siderophile elements (HSE) in the bulk martian mantle suggest that these elements were added after Mars' core formed. The shergottite-nakhlite-chassigny (SNC) meteorites imply an average mantle Pt abundance of ≈3 to 5 parts per billion, which requires the addition of 1.6 × 10 kilograms of chondritic material, or 0.

Origin of Phobos and Deimos by the impact of a Vesta-to-Ceres sized body with Mars.

It has been proposed that Mars' moons formed from a disk produced by a large impact with the planet. However, whether such an event could produce tiny Phobos and Deimos remains unclear. Using a hybrid -body model of moon accumulation that includes a full treatment of moon-moon dynamical interactions, we first identify new constraints on the disk properties needed to produce Phobos and Deimos.

TRITON'S EVOLUTION WITH A PRIMORDIAL NEPTUNIAN SATELLITE SYSTEM.

The Neptunian satellite system is unusual. The major satellites of Jupiter, Saturn and Uranus are all in prograde, low inclination orbits. Neptune on the other hand, has the fewest satellites and most of the system's mass is within one irregular satellite, Triton.

LUNAR VOLATILE DEPLETION DUE TO INCOMPLETE ACCRETION WITHIN AN IMPACT-GENERATED DISK.

The Moon may have formed from an Earth-orbiting disk of vapor and melt produced by a giant impact. The Moon and Earth's mantles have similar compositions. However, it is unclear why lunar samples are more depleted in volatile elements than terrestrial mantle rocks, given that an evaporative escape mechanism appears inconsistent with expected disk conditions.

Forming a Moon with an Earth-like composition via a giant impact.

In the giant impact theory, the Moon formed from debris ejected into an Earth-orbiting disk by the collision of a large planet with the early Earth. Prior impact simulations predict that much of the disk material originates from the colliding planet. However, Earth and the Moon have essentially identical oxygen isotope compositions.

Origin of Saturn's rings and inner moons by mass removal from a lost Titan-sized satellite.

The origin of Saturn's rings has not been adequately explained. The current rings are more than 90 to 95 per cent water ice, which implies that initially they were almost pure ice because they are continually polluted by rocky meteoroids. In contrast, a half-rock, half-ice mixture (similar to the composition of many of the satellites in the outer Solar System) would generally be expected.

Accretion of the Earth.

The origin of the Earth and its Moon has been the focus of an enormous body of research. In this paper I review some of the current models of terrestrial planet accretion, and discuss assumptions common to most works that may require re-examination. Density-wave interactions between growing planets and the gas nebula may help to explain the current near-circular orbits of the Earth and Venus, and may result in large-scale radial migration of proto-planetary embryos.

Forced resonant migration of Pluto's outer satellites by Charon.

Two small moons of Pluto have been discovered in low-eccentricity orbits exterior to Pluto's large satellite, Charon. All three satellite orbits are nearly coplanar, implying a common origin. It has been argued that Charon formed as a result of a giant impact with primordial Pluto.

A common mass scaling for satellite systems of gaseous planets.

The Solar System's outer planets that contain hydrogen gas all host systems of multiple moons, which notably each contain a similar fraction of their respective planet's mass (approximately 10(-4)). This mass fraction is two to three orders of magnitude smaller than that of the largest satellites of the solid planets (such as the Earth's Moon), and its common value for gas planets has been puzzling. Here we model satellite growth and loss as a forming giant planet accumulates gas and rock-ice solids from solar orbit.

A giant impact origin of Pluto-Charon.

Pluto and its moon, Charon, are the most prominent members of the Kuiper belt, and their existence holds clues to outer solar system formation processes. Here, hydrodynamic simulations are used to demonstrate that the formation of Pluto-Charon by means of a large collision is quite plausible. I show that such an impact probably produced an intact Charon, although it is possible that a disk of material orbited Pluto from which Charon later accumulated.