Factors Controlling Volcanism and Tectonism in Solar System Solid Bodies

1995 ◽  
pp. 47-49
Author(s):  
A. T. Basilevsky
Keyword(s):  
Solar System ◽  
Solid Bodies

The early Solar System and the rotation of the Sun

1984 ◽  
Vol 313 (1524) ◽  
pp. 39-45 ◽  
Keyword(s):  
Angular Momentum ◽  
Solar System ◽  
Magnetic Coupling ◽  
Central Star ◽  
The Sun ◽  
Early Solar System ◽  
Low Mass Stars ◽  
Hydrogen Burning ◽  
Low Mass ◽  
Solid Bodies

In most discussions of the formation of the Solar System, the early Sun is assumed to have possessed the bulk of the angular momentum of the system, and a closely surrounding disc of gas was spun out, which, through magnetic coupling, acquired a progressively larger proportion of the total angular momentum. There are difficulties with this model in accounting for the inclined axis of the Sun, the magnitude of the magnetic coupling required, and the nucleogenetic variations recently observed in the Solar System. Another possibility exists, namely that of a slowly contracting disc of interstellar material, leading to the formation of both a central star and a protoplanetary disc. In this model one can better account for the tilt of the Sun’s axis and the lack of mixing necessary to account for the nucleogenetic evidence. The low angular momentum of the Sun and of other low mass stars is then seen as resulting from a slow build-up as a degenerate dwarf, acquiring orbital material at a low specific angular momentum. When the internal temperature reaches the threshold for hydrogen burning, the star expands to the Main Sequence and is now a slow rotator. More massive stars would spin quickly because they had to acquire orbiting material after the expansion, and therefore at a high specific angular momentum. A process of gradual inward spiralling may also allow materials derived from different sources to accumulate into solid bodies, and be placed on a great variety of orbits in the outer reaches of the system, setting up the cometary cloud of uneven nucleogenetic composition.

Rotation of solid bodies in the solar system

1973 ◽  
Vol 11 (4) ◽  
pp. 767 ◽  
Author(s):  
S. J. Peale
Keyword(s):  
Solar System ◽  
Solid Bodies

Irradiation and accretion of solids in space based on observations of lunar rocks and grains

1977 ◽  
Vol 285 (1327) ◽  
pp. 69-95 ◽  
Keyword(s):  
Charged Particle ◽  
Solar System ◽  
Lunar Regolith ◽  
Quantitative Information ◽  
Origin And Evolution ◽  
Lunar Material ◽  
Electromagnetic Processes ◽  
Wide Range ◽  
Solid Bodies ◽  
Physical And Chemical

Clues to a wide range of questions relating to the origin and evolution of the solar system and dynamic physical and electromagnetic processes occurring concurrently and in the past in our galaxy have been provided by a study of the lunar samples. This information is deduced from a variety of complementary physical and chemical evidence. In this presentation, greatest emphasis is laid on information based on the cosmogenic effects, i.e. those arising from interactions of low energy cosmic rays with lunar surface materials. This information is generally not obtainable from examinations of meteorite samples, except in the case of certain types termed gas-rich meteorites, due to loss of their surface regions by atmospheric ablation. The present discussions will concern the nature of experimental data to date and implications thereof to the charged particle environment of the Moon, ancient magnetic fields and the nature of, time scales involved in the irradiation and accretion of solids in space, based on lunar regolith dynamics. It becomes clear that there does not yet exist any consensus on the absolute values of charged particle or the meteorite fluxes, and also about the details of the evolution of the lunar regolith. This would be expected also considering that one is dealing with phenomena which range in size/energy scales over many orders of magnitude and that the techniques used for the studies were only recently developed in many cases. The complex history of evolution of lunar material is slowly being understood and it is a hope that a great deal of quantitative information will soon be available which will in turn allow discussion of evolution of solid bodies in the solar system.

scholarly journals The Orbital Distribution and Origin of Meteoroids

1991 ◽  
Vol 126 ◽  
pp. 291-298
Author(s):  
Duncan Steel
Keyword(s):  
Solar System ◽  
Data Center ◽  
Source Function ◽  
Interplanetary Dust ◽  
Asteroid Belt ◽  
Meteoroid Streams ◽  
Origin And Evolution ◽  
Solid Bodies ◽  
Meteor Data

AbstractApproximately 68,000 orbits of meteoroids, ranging from sizes of 10 cm and more down to microgram masses, are now available through the IAU Meteor Data Center. These orbits were measured in surveys based in the U.S.S.R., the U.S.A., Canada, Somalia, and Australia, using photographic, radar and television techniques; the data represent our best knowledge of the orbital distributions of smaller solid bodies in the solar system. It is found that quite different distributions result in different mass regimes, with implications for the origin and evolution of these particles: for example the larger bodies, observed as fireballs, are associated with meteorites in coming from the region of the asteroid belt with low-inclination orbits, whereas the smaller meteoroids have more comet-like orbits. There is also evidence for several meteoroid streams associated with specific Apollo asteroids. The data may additionally be viewed as a suitable source function in investigations of the production of interplanetary dust from the fragmentation of larger meteoroids in mutual collisions. However, inspection of the data raises many questions: for instance there seem to be many meteoroids on small retrograde paths, but no possible parent objects are known to exist on such orbits.

Polarimetry: a primary tool for the physical characterization of asteroids

2014 ◽  
Vol 10 (S305) ◽  
pp. 313-318
Author(s):  
A. Cellino ◽  
S. Bagnulo
Keyword(s):  
Solar System ◽  
First Generation ◽  
Ground Truth ◽  
Preliminary Evidence ◽  
Physical Characterization ◽  
New Class ◽  
Solid Bodies ◽  
First Time

AbstractAsteroid polarimetry has taken profit in recent years of a renewed interest triggered by exciting results from observing campaigns and theoretical studies. One of the most important applications of polarimetry to asteroid studies is the derivation of the geometric albedo and of the typical sizes of the particles forming the regolith layer covering the surface. Moreover, the serendipitous discovery of a new class of asteroids displaying unusual polarimetric properties, the so-called “Barbarians”, has been followed by increasing evidence that these objects can be extremely primitive and may be interpreted as remnants of the very first generation of solid bodies accreted in the inner Solar System. In addition, some results of asteroid polarimetry are going to be interpreted, for the first time, in terms of some “ground truth” evidence, made possible by in situ observations of the surface of the asteroid (4) Vesta by the Dawn space probe. Finally, some preliminary evidence suggests that spectro-polarimetry is going to become a major tool for the physical characterization of the small bodies of the solar system.

Factors controlling volcanism and tectonism in solar system solid bodies

1994 ◽  
Vol 67 (1-3) ◽  
pp. 47-49 ◽  
Author(s):  
A. T. Basilevsky
Keyword(s):  
Solar System ◽  
Solid Bodies

scholarly journals Cometary Versus Asteroidal Origin of Chondritic Meteorites

1971 ◽  
Vol 12 ◽  
pp. 447-460 ◽  
Author(s):  
George W. Wetherill
Keyword(s):  
Solar System ◽  
Solar Nebula ◽  
Mineralogical Composition ◽  
Radioactive Isotopes ◽  
Interstellar Matter ◽  
The Moon ◽  
Isotopic Age ◽  
Short Period ◽  
History Of ◽  
Solid Bodies

Much of what we know about the early history of the solar system has been learned from the study of meteorites. This results from the fact, demonstrated by isotopic age measurements, that all of the various classes of stone and iron meteorites were formed 4.6 X 109 yr ago within a short period of time, probably less than 100 million yr in duration. This is also the age of Earth and the Moon and may be presumed to be the time of formation of the solid bodies in the solar system. Measurements of the products of the decay of the extinct radioactive isotopes 129Xe and 244Pu show, furthermore, that the formation of these solid bodies occurred within 100 million yr of the time of separation of the solar nebula from interstellar matter. Except for physical fragmentation into smaller bodies, the chemical and mineralogical composition of most meteorites has been essentially unaltered since this time during the formation interval of the solar system.

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