Related papers: A colossal impact enriched Mars' mantle with noble…
The nucleosynthetic isotope signatures of meteorites and the bulk silicate Earth (BSE) indicate that Earth consists of a mixture of "carbonaceous" (CC) and "non-carbonaceous" (NC) materials. We show that the fration of CC material recorded…
Mars shares many similarities and characteristics to Earth including various geological features and planetary structure. The remarkable bimodal distribution of elevations in both planets is one of the most striking global features…
Chondrites, the building blocks of the terrestrial planets, have mass and atomic proportions of oxygen, iron, magnesium, and silicon totaling $\geq$90\% and variable Mg/Si ($\sim$25\%), Fe/Si (factor of $\geq$2), and Fe/O (factor of…
We study the evolution of debris created in the giant impacts expected during the final stages of terrestrial planet formation. The starting point is the debris created in a simulation of the Moon-forming impact. The dynamical evolution is…
If properly interpreted, the impact record of the Moon, Earth's nearest neighbour, can be used to gain insights into how the Earth has been influenced by impacting events since its formation ~4.5 billion years (Ga) ago. However, the nature…
We compare the number of lunar craters larger than 15 km across and younger than 1.1 Ga to the estimates of the number of craters that could have been formed for 1.1 Ga if the number of near-Earth objects and their orbital elements during…
Dynamical scenarios of terrestrial planets formation involve strong perturbations of the inner part of the solar system by the giant-planets, leading to enhanced impact velocities and subsequent collisional erosion. We quantitatively…
Earth and Moon are shown here to be composed of oxygen isotope reservoirs that are indistinguishable, with a difference in {\Delta}"17O of -1 +/- 5ppm (2se). Based on these data and our new planet formation simulations that include a…
The Earth, Venus, Mars, and some extrasolar terrestrial planets have a mass and radius that is consistent with a mass fraction of about 30% metallic core and 70% silicate mantle. At the inner frontier of the solar system, Mercury has a…
In the leading theory of lunar formation, known as the giant impact hypothesis, a collision between two planet-size objects resulted in a young Earth surrounded by a circumplanetary debris disk from which the Moon later accreted. The range…
Seismic anisotropy, arising from the crystallographic or lattice-preferred orientation of anisotropic minerals or the shape-preferred orientation of melts or cracks, can establish a critical link between Mars's past evolution and its…
The final stage of planet formation is dominated by collisions between planetary embryos. The dynamics of this stage determine the orbital configuration and the mass and composition of planets in the system. In the solar system, late giant…
We simulate the collision of precursor icy moons analogous to Dione and Rhea as a possible origin for Saturn's remarkably young rings. Such an event could have been triggered a few hundred million years ago by resonant instabilities in a…
We present conclusions from a large number of N-body simulations of the giant impact phase of terrestrial planet formation. We focus on new results obtained from the recently proposed Grand Tack model, which couples the gas-driven migration…
We present Keck High Resolution Echelle Spectrometer (HIRES) observations and model atmosphere analysis for two nearby, cool, helium-dominated atmosphere white dwarfs that have been polluted by accretion: WD J1927-0355 and WD J2141-3300.…
The Earth's Moon is thought to have formed from a circumterrestrial disk generated by a giant impact between the proto-Earth and an impactor approximately 4.5 billion years ago. Since the impact was energetic, the disk would have been hot…
A framework for the theoretical and analytical understanding of the impact crater-size frequency distribution is developed and applied to observed data from Mars and Earth. The analitical model derived gives the crater population,N, as a…
We determined the possible compensation depths for relief harmonics of different degrees and orders. The relief is shown to be completely compensated within the depth range of 0 to 1400 km. The lateral distributions of compensation masses…
The solar system planets are benchmarks for the planet formation theory. Yet two paradigms coexist for the four terrestrial planets: the prolonged collisional growth among planetesimals lasting $>100$ million years (Myr) and the fast…
There is a wealth of evidence to suggest that planetary systems can survive beyond the main sequence. Most commonly, white dwarfs are found to be accreting material from tidally disrupted asteroids, whose bulk compositions are reflected by…