Related papers: A colossal impact enriched Mars' mantle with noble…
The planet Mercury possesses an anomalously large iron core, and a correspondingly high bulk density. Numerous hypotheses have been proposed in order to explain such a large iron content. A long-standing idea holds that Mercury once…
The detection of a dust disc around G29-38 and transits from debris orbiting WD1145+017 confirmed that the photospheric trace metals found in many white dwarfs arise from the accretion of tidally disrupted planetesimals. The composition of…
Multiple impact basins formed on the Moon about 3.8 Gyr ago in what is known as the lunar cataclysm or late heavy bombardment. Many workers currently interpret the lunar cataclysm as an impact spike primarily caused by main-belt asteroids…
According to the giant impact theory, the Moon formed through accreting the debris disk produced by a collision between Theia and the proto-Earth. The giant impact theory can explain most of the properties of the Earth-Moon system, however,…
Recent high precision meteoritic data infers that Mars finished its accretion rapidly within 10 Myr of the beginning of the Solar system and had an accretion zone that did not entirely overlap with the Earth's. Here we present a detailed…
Iapetus, the outermost regular satellite of Saturn, has a drastic albedo dichotomy and an equatorial circumferential ridge that reaches heights of 20 km and widths of 70 km. This moon is thought to have formed concurrently with Saturn, and…
Earth's surface environment is largely influenced by its budget of major volatile elements: carbon (C), nitrogen (N), and hydrogen (H). Although the volatiles on Earth are thought to have been delivered by chondritic materials, the…
During planet formation, numerous small impacting bodies result in cratering impacts on large target bodies. A fraction of the target surface is eroded, while a fraction of the impactor material accretes onto the surface. These fractions…
The Moon holds important clues to the early evolution of the Solar System. Some 50 impact basins (crater diameter D>300 km) have been recognized on the lunar surface, implying that the early impact flux was much higher than it is now. The…
Polluted white dwarfs serve as astrophysical mass spectrometers - their photospheric abundances are used to infer the composition of planetary objects that accrete onto them. We show that due to asymmetries in the accretion process, the…
Giant impacts dominate the final stages of terrestrial planet formation and set the configuration and compositions of the final system of planets. A giant impact is believed to be responsible for the formation of Earth's Moon, but the…
The existence of possible early oceans in the northern hemisphere of Mars has been researched and debated for decades. The nature of the early martian climate is still somewhat mysterious, but evidence for one or more early oceans implies…
We show that a model in which Mars grows near Earth and Venus but is then scattered out of the terrestrial region yields a natural pathway to explain the low masses of the Martian moons Phobos & Deimos. In this scenario, the last giant…
A remarkable discovery of NASA's Kepler mission is the wide diversity in the average densities of planets of similar mass. After gas disk dissipation, fully formed planets could interact with nearby planetesimals from a remnant planetesimal…
Mars finished forming while the solar nebula was still present, and acquired its primordial atmosphere from this reservoir. The absence of a detectable cometary xenon signature in the present-day Martian atmosphere suggests that the capture…
Of the solar system's four terrestrial planets, the origin of Mercury is perhaps the most mysterious. Modern numerical simulations designed to model the dynamics of terrestrial planet formation systematically fail to replicate Mercury;…
The lunar farside highlands problem refers to the curious and unexplained fact that the farside lunar crust is thicker, on average, than the nearside crust. Here we recognize the crucial influence of Earthshine, and propose that it…
In the giant impact hypothesis for lunar origin, the Moon accreted from an equatorial circum-terrestrial disk; however the current lunar orbital inclination of 5 degrees requires a subsequent dynamical process that is still debated. In…
Planets and stars are expected to be compositionally linked because they accrete from the same material reservoir. However, astronomical observations revealed the existence of exoplanets whose bulk density is far higher than what is…
We simulate the hypothesised collision between the proto-Earth and a Mars-sized impactor that created the Moon. Amongst the resulting debris disk in some impacts, we find a self-gravitating clump of material. It is roughly the mass of the…