相关论文: Stability of organic molecules against shocks in t…
Observations of comets and asteroids show that the Solar Nebula that spawned our planetary system was rich in water and organic molecules. Bombardment brought these organics to the young Earth's surface, seeding its early chemistry. Unlike…
Chondrules are mm-sized spherules found throughout primitive, chondritic meteorites. Flash heating by a shock front is the leading explanation of their formation. However, identifying a mechanism for creating shock fronts inside the solar…
It has been suggested that shock waves in the solar nebula formed the high temperature materials observed in meteorites and comets. It is shown that the temperatures at the inner rim of the solar nebula could have been high enough over a…
Chondrules are important early Solar System materials that can provide a wealth of information on conditions in the solar nebula, if their formation mechanism can be understood. The theory most consistent with observational constraints,…
Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous…
Beneath the fusion-encrusted surfaces of the most primitive stony meteorites lies not homogeneous rock, but a profusion of millimeter-sized igneous spheres. These chondrules, and their centimeter-sized counterparts, the…
Chondritic meteorites constitute the most ancient rock record available in the laboratory to study the formation of the solar system and its planets. Detailed investigations of their mineralogy, petrography, chemistry and isotopic…
Chondrules represent one of the best probes of the physical conditions and processes acting in the early solar nebula. Proposed chondrule formation models are assessed based on their ability to match the meteoritic evidence, especially…
The late stages of stellar evolution from asymptotic giant branch stars to planetary nebulae are now known to be an active phase of molecular synthesis. Over 80 gas-phase molecules have been detected through rotational transitions in the…
A high fraction of carbon bound in solid carbonaceous material is observed to exist in bodies formed in the cold outskirts of the solar nebula, while bodies in the terrestrial planets region contain nearly none. We study the fate of the…
The building blocks of life, amino acids and nucleobases, are believed to have been synthesized in the extreme conditions that prevail in space starting from simple molecules containing hydrogen, carbon, oxygen and nitrogen. However, the…
Small bodies are the remnant building blocks from the time when the planets formed and migrated to their current positions. Their volatile composition and relative abundances serve as time capsules for the formation conditions in the…
Thermochemical modeling and shock-tube experiments show that shocks applied to N$_2$/CH$_4$ gas mixtures can synthesize organic molecules. Sufficiently large, hypersonic meteoroids entering the atmosphere of Saturn's moon Titan should…
We investigate the propagation of a shock wave into a warm neutral medium and cold neutral medium by one-dimensional hydrodynamic calculations with detailed treatment of thermal and chemical processes. Our main result shows that thermal…
Comets hold answers to mysteries of the Solar System by recording presolar history, the initial states of planet formation and prebiotic organics and volatiles to the early Earth. Analysis of returned samples from a comet nucleus will…
Conditions in the protosolar nebula have left their mark in the composition of cometary volatiles, thought to be some of the most pristine material in the solar system. Cometary compositions represent the end point of processing that began…
Meteorites, and in particular primitive meteorites (chondrites), are irreplaceable probes of the solar protoplanetary disk. We review their essential properties and endeavour to place them in astrophysical context. The earliest solar system…
We propose that the nebular shocks currently favored as a model to form chondrules and other annealed silicates in the solar nebula originate in the dynamical activity present in the envelope of forming Jovian planets. In contrast to the…
The formation of chondrules in the protoplanetary nebulae causes many questions concerning the formation process, the source of energy for melting the rims, and the composition of the origin material. The aim of this work is to explore the…
Chondrite meteorites are believed to represent the building blocks of the solar nebula, out of which our solar system formed. They are a mixture of silicate and oxide objects (chondrules and refractory inclusions) that experienced extremely…