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Radionuclides with half-lives ranging from some years to billions of years presumably synthesized outside of the solar system are now recorded in ``live'' or ``fossil'' form in various types of materials, like meteorites or the galactic…

Astrophysics · Physics 2009-10-31 Marcel Arnould , Nikos Prantzos

We review the abundance and diversity of terrestrial rock hosted life, the environments it inhabits, the evolution of its metabolisms, and its fossil biomarkers to provide guidance in the search for the biomarkers of rock hosted life on…

Earth and Planetary Astrophysics · Physics 2019-10-16 T. C. Onstott , B. L. Ehlmann , H. Sapers , M. Coleman , M. Ivarsson , J. J. Marlow , A. Neubeck , P. Niles

Chondrites are the likely building blocks of Earth, and identifying the group of chondrite that best represents Earth is a key to resolving the state of the early Earth. The origin of chondrites, however, remains controversial partly…

Earth and Planetary Astrophysics · Physics 2021-03-10 Yoshinori Miyazaki , Jun Korenaga

White dwarfs that accrete the debris of tidally disrupted asteroids provide the opportunity to measure the bulk composition of the building blocks, or fragments, of exoplanets. This technique has established a diversity in compositions…

Earth and Planetary Astrophysics · Physics 2021-02-15 Mark A. Hollands , Pier-Emmanuel Tremblay , Boris T. Gänsicke , Detlev Koester , Nicola P. Gentile-Fusillo

Ice crystals growing in highly supersaturated air at temperatures near -5 C exhibit a distinctive, nonplanar dendritic morphology that has not been previously documented or explained. We examine this structure and identify its most…

Materials Science · Physics 2009-12-15 Kenneth G. Libbrecht

The photospheres of some white dwarfs are "polluted" by accretion of material from their surrounding planetary debris. White dwarfs with dust disks are often heavily polluted and high-resolution spectroscopic observations of these systems…

Solar and Stellar Astrophysics · Physics 2020-01-08 Siyi Xu , Patrick Dufour , Beth Klein , Carl Melis , Nathaniel N. Monson , B. Zuckerman , Edward D. Young , Michael A. Jura

The remanent magnetisation of meteorite material in the solar system indicates that magnetic fields of several Gauss are present in the protoplanetary disk. It is shown that such relativelystrong magnetic fields can be generated in dusty…

Astrophysics · Physics 2007-05-23 G. T. Birk , H. Wiechen , A. Kopp , H. Lesch

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…

Earth and Planetary Astrophysics · Physics 2023-09-14 Andrew Swan , Jay Farihi , Carl Melis , Patrick Dufour , Steven J. Desch , Detlev Koester , Jincheng Guo

Dust particles are the building blocks from which planetary bodies are made. A major goal of the studies of planet-forming disks is to constrain the properties of dust particles and aggregates in order to trace their origin, structure, and…

Earth and Planetary Astrophysics · Physics 2023-08-16 Christian Ginski , Ryo Tazaki , Carsten Dominik , Tomas Stolker

The cosmic dust particles found in space are mainly porous aggregates of smaller grains. Theoretically, these aggregates are replicated using fractal geometry, assuming a cluster of spheres. Although, the light scattering response of cosmic…

Earth and Planetary Astrophysics · Physics 2023-04-14 Prithish Halder , Sujan Sengupta

Large numbers of small opaque dust clouds - termed 'globulettes' by Gahm et al - have been observed in the H II regions surrounding young stellar clusters. With masses typically in the planetary (or low mass brown dwarf) regime, these…

Earth and Planetary Astrophysics · Physics 2015-06-23 Thomas J. Haworth , Stefano Facchini , Cathie J. Clarke

Ordinary chondrites (OCs) are by far the most abundant meteorites (80% of all falls). Their origin has long been the matter of a heated debate. About thirty years ago (e.g., Pellas 1988), it was proposed that OCs should originate from…

Earth and Planetary Astrophysics · Physics 2016-12-07 Pierre Vernazza , Brigitte Zanda , Tomoki Nakamura , Edward Scott , Sara Russell

We review recent studies of organic molecule formation in dense molecular clouds and in comets. We summarise the known organic inventories of molecular clouds and recent comets, particularly Hale-Bopp. The principal chemical formation…

Astrophysics · Physics 2009-11-06 S. B. Charnley , S. D. Rodgers , Y-J. Kuan , H-C. Huang

This work purports to help understand the InterStellar Extinction Curve in and near the visible range. In this range, crystalline materials are known to be transparent, so amorphous dust is needed. Molecular modeling experiments are used to…

Astrophysics of Galaxies · Physics 2019-05-21 Renaud Papoular

Cometary dust particles are remnants of the primordial accretion of refractory material that occurred during the initial stages of the Solar System formation. Understanding their physical structure can help constrain their accretion…

Within the framework of The Heterogeneous dust Evolution Model at the IaS (THEMIS) this work investigates in detail the surface processes and chemistry relating to core/mantle interstellar and cometary grain structures and its influence on…

Astrophysics of Galaxies · Physics 2021-11-09 A. P. Jones

Ubiquitously found in the Universe, atomic hydrogen represents up to 70% of the neutral gas composition of the Milky Way. As an adatom, hydrogen can physisorb or chemisorb onto interstellar dust grains and icy mantles, thereby contributing…

Astrophysics of Galaxies · Physics 2026-03-25 Dubois David , Guichard Pierre , Pasquier Remi

Observations of dusty debris disks can be used to test theories of planetesimal coagulation. Planetesimals of sizes up to a couple thousand kms are embedded in these disks and their mutual collisions generate the small dust grains that are…

Earth and Planetary Astrophysics · Physics 2011-10-03 Andrew B. Shannon , Yanqin Wu

Carbon macromolecules are intermediates between small gas-phase species and larger dust structures. I illustrate how observations and dedicated laboratory experiments support this picture.

Astrophysics of Galaxies · Physics 2022-08-18 Christine Joblin

The formation of complex organic molecules (COMs) in protostellar environments is a hotly debated topic. In particular, the relative importance of the gas phase processes as compared to a direct formation of COMs on the dust grain surfaces…

Earth and Planetary Astrophysics · Physics 2015-06-23 C. Codella , F. Fontani , C. Ceccarelli , L. Podio , S. Viti , R. Bachiller , M. Benedettini , B. Lefloch
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