相关论文: Chondrules and Nebular Shocks
We obtained mid-infrared spectra of chondrules, matrix, CAIs and bulk material from primitive type 1-4 chondrites in order to compare them with the dust material in young, forming solar systems and around comets. Our aim is to investigate…
Recent laboratory efforts (Fu et al., 2014) have constrained the remanent magnetizations of chondrules and the magnetic field strengths at which the chondrules were exposed to as they cooled below their Curie points. An outstanding question…
The effect of a nearby $\gamma$-ray burst (GRB) on the preplanetary solar nebula is considered. The intense irradiation by x-rays and $\gamma$-rays would have caused dust balls to become molten in a matter of seconds, cooling more slowly to…
We study magnetic field steepening due to ambipolar diffusion (Brandenburg & Zweibel 1994) in protoplanetary disk environments and draw the following conclusions. Current sheets are generated in magnetically active regions of the disk where…
The porosity of an asteroid is important when studying the evolution of our solar system through small bodies and for planning mitigation strategies to avoid disasters due to asteroid impacts. Our knowledge of asteroid porosity largely…
Chondrules are considered to have much information on dust particles and processes in the solar nebula. It is naturally expected that protoplanetary disks observed in present star forming regions have similar dust particles and processes,…
In order to investigate the hypothesis that dust aggregates were transformed to meteoritic chondrules by nebular lightning, we exposed silicatic and metallic dust samples to electric discharges with energies of 120 to 500 J in air at…
Compound chondrules, i.e. chondrules fused together, make a powerful probe of the density and compositional diversity in chondrule-forming environments, but their abundance among the dominating porphyritic textures may have been drastically…
Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most…
The formation of planetesimals in the early Solar System is hardly understood, and in particular the growth of dust aggregates above millimeter sizes has recently turned out to be a difficult task in our understanding [Zsom et al. 2010,…
Meteoritical and astrophysical models of planet formation make contradictory predictions for dust concentration factors in chondrule forming regions of the solar nebula. Meteoritical and cosmochemical models strongly suggest that…
The bulk volatile contents of chondritic meteorites provide clues to their origins. Matrix and chondrules carry differing abundances of moderately volatile elements, with chondrules carrying a refractory signature. At the high temperatures…
Meteoritic chondrules were formed in the early solar system by brief heating of silicate dust to melting temperatures. Some highly refractory grains (Type B calcium-aluminum-rich inclusions, CAIs) also show signs of transient heating. A…
Several lines of evidence suggest that fine silicate crystals observed in primitive meteorite and interplanetary dust particles (IDPs) nucleated in a supersaturated silicate vapor followed by crystalline growth. We investigated evaporation…
We propose that chondrules and chondrites formed together during a brief radiative heating event caused by the close encounter of a small (m to km-scale), primitive planetesimal (SPP) with incandescent lava on the surface of a large (100…
We propose that chondrules are formed by radiative heating of pre-existing dust clumps during close fly-bys of planetesimals with incandescent lava at their surfaces. We show that the required temperatures and cooling rates are easily…
We use radiation hydrodynamics with direct particle integration to explore the feasibility of chondrule formation in planetary embryo bow shocks. The calculations presented here are used to explore the consequences of a Mars-size planetary…
Early Solar System (SS) planetesimals constitute the parent bodies of most meteorites investigated today. Nucleosynthetic isotope anomalies of bulk meteorites have revealed a dichotomy between non-carbonaceous (NC) and carbonaceous (CC)…
Understanding the origin of comets requires knowledge of how the Solar System formed from a cloud of dust and gas 4.567 Gyr ago. Here, a review is presented of how the remnants of this formation process, meteorites and to a lesser extent…
Chondrule formation remains one of the most elusive early Solar System events. Here, we take the novel approach of employing numerical simulations to investigate chondrule origin beyond purely cosmochemical methods. We model the transport…