Electron Microscopy and Microanalysis of Metal Phases in Meteorites

1998 ◽  
Vol 4 (S2) ◽  
pp. 602-603
Author(s):  
D. B. Williams ◽  
J. I. Goldstein
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Solar System ◽  
Asteroid Belt ◽  
Detailed Knowledge ◽  
Full Understanding ◽  
Beam Analysis ◽  
History Of ◽  
Metal Phases

Meteorites are remnants of the primordial material from which the solar system condensed. Most meteorites originated in the asteroid belt between Mars and Jupiter and fell to earth when their orbits were disturbed by collisions. Metal phases are present in all types of meteorites and are alloys of Fe and Ni containing S and P. The study of metal meteorites has yielded valuable information about the early thermal history of the solar system, since their heat treatment has been preserved in the microstructure and microchemistry of the meteorites and can be discerned by electron microscopy and microanalysis. A full understanding of the structure and chemistry of meteorites requires detailed knowledge of the Fe-Ni, Fe-Ni-S and Fe-Ni-P phase diagrams and determination of these diagrams has been carried out over more than three decades of electron-beam analysis by the authors.

scholarly journals In Situ exploration of the giant planets

2021 ◽  
Author(s):  
O. Mousis ◽  
D. H. Atkinson ◽  
R. Ambrosi ◽  
S. Atreya ◽  
D. Banfield ◽  
...  
Keyword(s):  
Solar System ◽  
Giant Planets ◽  
Atmospheric Composition ◽  
Formation History ◽  
History Of ◽  
Composition Structure ◽  
Galileo Probe ◽  
Probe Measurements

AbstractRemote sensing observations suffer significant limitations when used to study the bulk atmospheric composition of the giant planets of our Solar System. This impacts our knowledge of the formation of these planets and the physics of their atmospheres. A remarkable example of the superiority of in situ probe measurements was illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases’ abundances and the precise measurement of the helium mixing ratio were only made available through in situ measurements by the Galileo probe. Here we describe the main scientific goals to be addressed by the future in situ exploration of Saturn, Uranus, and Neptune, placing the Galileo probe exploration of Jupiter in a broader context. An atmospheric entry probe targeting the 10-bar level would yield insight into two broad themes: i) the formation history of the giant planets and that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. An atmospheric probe could represent a significant ESA contribution to a future NASA New Frontiers or flagship mission to be launched toward Saturn, Uranus, and/or Neptune.

scholarly journals The Principle of Least Interaction Action

1974 ◽  
Vol 3 ◽  
pp. 489-489
Author(s):  
M. W. Ovenden
Keyword(s):  
Solar System ◽  
Planetary System ◽  
Satellite System ◽  
Asteroid Belt ◽  
Correct Prediction ◽  
The Sun ◽  
Approximate Methods ◽  
Satellites Of Jupiter ◽  
History Of ◽  
Minimum Interaction

AbstractThe intuitive notion that a satellite system will change its configuration rapidly when the satellites come close together, and slowly when they are far apart, is generalized to ‘The Principle of Least Interaction Action’, viz. that such a system will most often be found in a configuration for which the time-mean of the action associated with the mutual interaction of the satellites is a minimum. The principle has been confirmed by numerical integration of simulated systems with large relative masses. The principle lead to the correct prediction of the preference, in the solar system, for nearly-commensurable periods. Approximate methods for calculating the evolution of an actual satellite system over periods ˜ 109 yr show that the satellite system of Uranus, the five major satellites of Jupiter, and the five planets of Barnard’s star recently discovered, are all found very close to their respective minimum interaction distributions. Applied to the planetary system of the Sun, the principle requires that there was once a planet of mass ˜ 90 Mθ in the asteroid belt, which ‘disappeared’ relatively recently in the history of the solar system.

scholarly journals Thermal evolution and sintering of chondritic planetesimals

2018 ◽  
Vol 615 ◽  
pp. A147 ◽  
Author(s):  
Hans-Peter Gail ◽  
Mario Trieloff
Keyword(s):  
Solar System ◽  
Temperature Dependence ◽  
Heat Conductivity ◽  
Thermal Evolution ◽  
Scattering Length ◽  
Full Range ◽  
Asteroid Belt ◽  
Published Data ◽  
Detailed Knowledge ◽  
Micro Cracks

Context. Understanding the compaction and differentiation of the planetesimals that formed during the initial phases of our solar system and the protoplanets from the asteroid belt and the terrestrial planet region of the solar system requires a reliable modelling of their internal thermal evolution. An important ingredient for this is a detailed knowledge of the heat conductivity, K, of the chondritic mixture of materials from which planetesimals are formed. The dependence of K on the composition and structure of the material was studied in the previous study of this series. For the second important aspect, the dependence of K on temperature, laboratory investigations on a number of meteorites exist concerning the temperature variation of K, but no explanation for the observed variation has been given yet. Aims. We evaluate the temperature dependence of the heat conductivity of the solid chondritic material from the properties of its mixture components from a theoretical model. This allows us to predict the temperature-dependent heat conductivity for the full range of observed meteoritic compositions and also for possible other compositions. Methods. Published results on the temperature dependence of the heat conductivity of the mineral components found in chondritic material are fitted to the model of Callaway for heat conductivity in solids by phonons. For the Ni, Fe-alloy, published laboratory data are used. The heat conductivity of chondritic material then is calculated by means of mixing rules. The role of micro-cracks is studied, which increase the importance of wall scattering for phonon-based heat conductivity. Results. Our model is applied to published data on the heat conductivity of individual chondrites. The general trends for the dependency of K on temperature found in laboratory experiments can largely be reproduced for the set of meteorites if the heat conductivity is calculated for a given composition from the properties of its constituents. It is found that micro-cracks have a significant impact on the temperature dependence of K because of their reduction of phonon scattering length.

The Effects of Processing on the Morphology of Nanoparticles

2004 ◽  
Vol 818 ◽  
Author(s):  
Christopher R. Perrey ◽  
Julia M. Deneen ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
Cost Effective ◽  
Production Method ◽  
Nanoscale Materials ◽  
Transmission Electron ◽  
Nanoparticle Morphology ◽  
History Of ◽  
Social Applications ◽  
Individual Nanoparticles

AbstractOne of the major challenges confronting the utilization of nanoparticles in industrial and social applications is that of producing the nanoscale materials. Of the methods of manufacturing nanoscale materials, processes involving plasmas have been shown to be cost-effective and versatile in the production of chemically diverse material. Using transmission electron microscopy, individual nanoparticles produced by a thermal plasma-based production method have been examined. The observations of these studies imply that the thermal history of the nanoparticles during formation is of great importance in the determination of the resulting nanoparticle morphology. Such results have the potential to enable the manufacturing of nanoparticles of a specific size and shape from plasmas.

scholarly journals The Non-carbonaceous–Carbonaceous Meteorite Dichotomy

2020 ◽  
Vol 216 (4) ◽  
Author(s):  
T. Kleine ◽  
G. Budde ◽  
C. Burkhardt ◽  
T. S. Kruijer ◽  
E. A. Worsham ◽  
...  
Keyword(s):  
Solar System ◽  
Terrestrial Planet ◽  
Building Blocks ◽  
Asteroid Belt ◽  
Primitive Mantle ◽  
Volatile Species ◽  
Rapid Formation ◽  
History Of ◽  
Carbonaceous Meteorite ◽  
Siderophile Elements

Abstract The isotopic dichotomy between non-carbonaceous (NC) and carbonaceous (CC) meteorites indicates that meteorite parent bodies derive from two genetically distinct reservoirs, which presumably were located inside (NC) and outside (CC) the orbit of Jupiter and remained isolated from each other for the first few million years of the solar system. Here we review the discovery of the NC–CC dichotomy and its implications for understanding the early history of the solar system, including the formation of Jupiter, the dynamics of terrestrial planet formation, and the origin and nature of Earth’s building blocks. The isotopic difference between the NC and CC reservoirs is probably inherited from the solar system’s parental molecular cloud and has been maintained through the rapid formation of Jupiter that prevented significant exchange of material from inside (NC) and outside (CC) its orbit. The growth and/or migration of Jupiter resulted in inward scattering of CC bodies, which accounts for the co-occurrence of NC and CC bodies in the present-day asteroid belt and the delivery of presumably volatile-rich CC bodies to the growing terrestrial planets. Earth’s primitive mantle, at least for siderophile elements like Mo, has a mixed NC–CC composition, indicating that Earth accreted CC bodies during the final stages of its growth, perhaps through the Moon-forming giant impactor. The late-stage accretion of CC bodies to Earth is sufficient to account for the entire budget of Earth’s water and highly volatile species.

Characterization of Plasma Immersion Deposited Multilayer Coatings by Ion Beam Techniques Combined with Energy Filtered Transmission Electron Microscopy

2005 ◽  
Vol 908 ◽  
Author(s):  
Florian Schwarz ◽  
Joerg K. N. Lindner ◽  
Maik Häeberlen ◽  
Goetz Thorwarth ◽  
Claus Hammerl ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Ion Beam ◽  
Hard Coatings ◽  
Elemental Distribution ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Detection Analysis ◽  
Transmission Electron ◽  
Beam Analysis

AbstractMultilayered and nanostructured coatings of amorphous carbon (DLC), silicon composite multilayers and nanocluster containing films today have great potential for applications as hard coatings, wear reduction layers and as diffusion barriers in biomaterials. Plasma immersion ion implantation and deposition (PIII&D) is a powerful technique to synthesize such films. The quantitative nanoscale analysis of the elemental distribution in such multielemental films and thin film stacks however is demanding.In this paper it is shown how the high spatial resolution capabilities of energy filtered trans-mission electron microscopy (EFTEM) chemical analysis can be combined with accurate and standard-less concentration determination of ion beam analysis (IBA) techniques like Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analysis (ERDA) to achieve absolute and accurate multielement concentration profiles in complicated nanomaterials.

GAUSS: Towards Sample Return from Dwarf Planet Ceres

2020 ◽  
Author(s):  
Xian Shi ◽  
Keyword(s):  
Solar System ◽  
Asteroid Belt ◽  
Global Ocean ◽  
Geological Time ◽  
Sample Return ◽  
Dawn Mission ◽  
Dwarf Planets ◽  
Geological Features ◽  
History Of ◽  
Physical And Chemical

<p>GAUSS (Genesis of Asteroids and EvolUtion of the Solar System) is a mission concept for the future exploration of Ceres. As both the largest resident of the main asteroid belt and the only dwarf planet in the inner Solar System, Ceres holds critical information for probing the evolution and habitability of our Solar System. NASA’s DAWN mission performed the by far most comprehensive investigation of Ceres during its over three year in-orbit operation around this unique world. Data collected by remote sensing instruments revealed an amazingly diverse landscape comprising different types of geological features. Beneath its volatile- and organic-rich surface, Ceres might have once possessed a global ocean, the remnants of which possibly still exist today as pockets of brine between the mantle and the crust. Hydrothermal activities that took place in recent geological time transferred materials deep inside Ceres to its surface, forming several outstanding surface features that are optimal for future sampling. Similar processes could occur on other ocean worlds in the Solar System, making Ceres a benchmark case for studying the evolution and habitability of these objects in general.</p> <p>To fully understand the physical and chemical evolution of Ceres, high resolution analyses of samples are necessary. With cryogenic sample return as its final step, the GAUSS project aims to answer the following key questions:</p> <ul> <li>What is the origin of Ceres and the origin and transfer of water and other volatiles in the inner solar system?</li> <li>What are the physical properties and internal structure of Ceres? What do they tell us about the evolutionary and aqueous alteration history of icy dwarf planets?</li> <li>What are the astrobiological implications of Ceres? Was it habitable in the past and is it still today?</li> <li>What are the mineralogical connections between Ceres and our current collections of primitive meteorites?</li> </ul>

scholarly journals GAUSS - A Sample Return Mission to Ceres

2020 ◽  
Author(s):  
Xian Shi ◽  
Keyword(s):  
Solar System ◽  
Remote Sensing Data ◽  
White Paper ◽  
Asteroid Belt ◽  
Sample Return ◽  
Dawn Mission ◽  
History Of ◽  
System 2 ◽  
Sample Return Mission ◽  
And Migration

<p>Ceres, the largest resident in the main asteroid belt and the innermost dwarf planet of the solar system, shares characteristics with a broad diversity of solar system objects, making it one of the most intriguing targets for planetary exploration. The recently completed Dawn mission through its 3.5 years of in-orbit investigation has furthered our understanding of Ceres, yet at the same time opened up more questions. Remote sensing data revealed that Ceres is rich in volatiles and organics, with fresh traces of cryovolcanic and geothermal activities. There is potential evidence of Ceres’ past and present habitability. Findings by Dawn suggest that Ceres might once be an ocean world and have undergone more complicated evolution than originally expected. Thus, Ceres encapsulates key information for understanding the history of our solar system and the origin of life, which has yet to be explored by future missions.</p><p>We present the GAUSS project (Genesis of Asteroids and EvolUtion of the Solar System), recently proposed as a white paper to ESA’s Voyage 2050 program. GAUSS is a mission concept of future exploration of Ceres with sample return as the primary goal. It aims to address the following top-level scientific questions concerning: 1) the origin and migration of Ceres and its implications on the water and volatile distribution and transfer in the inner solar system; 2) the internal structure and evolution of Ceres; 3) Ceres’ past and present-day habitability; and 4) mineralogical connections between Ceres and collections of primitive meteorites. We will discuss scientific objectives of Ceres exploration in post-Dawn era as well as instrumentation required for achieving them. We will explore candidate landing and sampling sites of high scientific interest based on Dawn results. We will also consider technical and financial feasibility of different mission scenarios in the context of broad international collaboration.</p>

scholarly journals Shaping of the Inner Solar System by the Gas-Driven Migration of Jupiter

2012 ◽  
Vol 8 (S293) ◽  
pp. 204-211
Author(s):  
Kevin J. Walsh ◽  
Alessando Morbidelli ◽  
Sean N. Raymond ◽  
David P. O'Brien ◽  
Avi M. Mandell
Keyword(s):  
Solar System ◽  
Dynamical Behavior ◽  
Terrestrial Planet ◽  
Giant Planets ◽  
Asteroid Belt ◽  
Radial Migration ◽  
Migration History ◽  
Order Of Magnitude ◽  
History Of ◽  
Outward Migration

AbstractA persistent difficulty in terrestrial planet formation models is creating Mars analogs with the appropriate mass: Mars is typically an order of magnitude too large in simulations. Some recent work found that a small Mars can be created if the planetesimal disk from which the planets form has an outermost edge at 1.0 AU. However, that work and no previous work could produce a truncation of the planetesimal disk while also explaining the mass and structure of the asteroid belt. We show that gas-driven migration of Jupiter inward to 1.5 AU, before its subsequent outward migration, can truncate the disk and repopulate the asteroid belt. This dramatic migration history of Jupiter suggests that the dynamical behavior of our giant planets was more similar to that inferred for extra-solar planets than previously thought, as both have been characterised by substantial radial migration.

scholarly journals Main-Belt Comets as Tracers of Ice in the Inner Solar System

2012 ◽  
Vol 8 (S293) ◽  
pp. 212-218 ◽  
Author(s):  
Henry H. Hsieh
Keyword(s):  
Solar System ◽  
Asteroid Belt ◽  
Main Belt ◽  
Small Bodies ◽  
Water Ice ◽  
History Of ◽  
Compositional History ◽  
Main Asteroid Belt ◽  
Abundance And Distribution ◽  
Ice Sublimation

AbstractAs a recently recognized class of objects exhibiting apparently cometary (sublimation-driven) activity yet orbiting completely within the main asteroid belt, main-belt comets (MBCs) have revealed the existence of present-day ice in small bodies in the inner solar system and offer an opportunity to better understand the thermal and compositional history of our solar system, and by extension, those of other planetary systems as well. Achieving these overall goals, however, will require meeting various intermediate research objectives, including discovering many more MBCs than the currently known seven objects in order to ascertain the population's true abundance and distribution, confirming that water ice sublimation is in fact the driver of activity in these objects, and improving our understanding of the physical, dynamical, and thermal evolutionary processes that have acted on this population over the age of the solar system.

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