相关论文: Magma ascent in planetesimals: control by grain si…
Context. To form metre-sized pre-planetesimals in protoplanetary discs, growing grains have to decouple from the gas before they are accreted onto the central star during their phase of fast radial migration and thus overcome the so-called…
We provide estimates of volcanism versus time for planets with Earth-like composition and masses from 0.25 to 25 times Earth, as a step toward predicting atmospheric mass on extrasolar rocky planets. Volcanism requires melting of the…
In the standard scenario of planet formation, terrestrial planets and the cores of the giant planets are formed by accretion of planetesimals. As planetary embryos grow the planetesimal velocity dispersion increases due to gravitational…
We have investigated the planetesimal accretion rate onto giant planets that are growing through gas accretion, using numerical simulations and analytical arguments. We derived the condition for gap opening in the planetesimal disk, which…
We investigate the melt production of planetary impacts as a function of planet size ($R/R_\mathrm{Earth}$=0.1-1.5), impactor size ($L$=1-1000 km), and core size ratio ($R_\mathrm{core}/R$=0.2-0.8) using a combination of parameterized…
We study protoplanetary disc evolution assuming that angular momentum transport is driven by gravitational instability at large radii, and magnetohydrodynamic (MHD) turbulence in the hot inner regions. At radii of the order of 1 AU such…
We present the first results from simulations of processes leading to planet formation in protoplanetary disks with different metallicities. For a given metallicity, we construct a two-dimensional grid of disk models with different initial…
Planetesimal formation via the streaming and gravitational instabilities of dust in protoplanetary disks requires a local enhancement of the dust-to-gas mass ratio. Radial drift of large grains toward pressure bumps in gas disks is a…
The thermal structure of a protoplanetary disc is regulated by the opacity that dust grains provide. However, previous works have often considered simplified prescriptions for the dust opacity in hydrodynamical disc simulations, e.g. by…
The solar and extra solar gas giants appear to have diverse internal structure and metallicities. We examine a potential cause for these dispersions in the context of the conventional sequential accretion formation scenario. In principle,…
We review the formation of large-scale heterogeneity in the solid Earth from the magma ocean phase to the present day, focusing on lower-mantle structure and evolution, as well as continental formation and its impact on interior-exterior…
We model the early stages of planet formation in the Solar System, including continual planetesimal formation, and planetesimal and pebble accretion onto planetary embryos in an evolving disk driven by a disk wind. The aim is to constrain…
The formation of a solar system is believed to have followed a multi-stage process around a protostar. Whipple first noted that planetesimal growth by particle agglomeration is strongly influenced by gas drag; there is a "bottleneck" at the…
In the hot-start core accretion formation model for gas giants, the interior of a planet is usually assumed to be fully convective. By calculating the detailed internal evolution of a planet assuming hot start outer boundary conditions, we…
Terrestrial planet formation (TPF) is a difficult problem that has vexed researchers for decades. Numerical models are only partially successful at reproducing the orbital architecture of the inner planets, but have generally not considered…
One of first the stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs much before the dispersal of most of the gas from the…
Observations and models of giant planets indicate that such objects are enriched in heavy elements compared to solar abundances. The prevailing view is that giant planets accreted multiple Earth masses of heavy elements after the end of…
We study the role of grain size in the rheological behaviour of calcite aggregates in the semi-brittle regime. We conduct triaxial deformation tests on three rocks, Solnhofen limestone, Carrara marble and Wombeyan marble, with average grain…
Context: The formation of rocky planetesimals is a long-standing problem in planet formation theory. One of the possibilities is that it results from gravitational instability as a result of pile-up of small silicate dust particles released…
The impact heat accumulated during the late stage of planetary accretion can melt a significant part or even the entire mantle of a terrestrial body, giving rise to a global magma ocean. [...] Assuming fractional crystallization of the…