Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 1974
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1974ap%26ss..29...63a&link_type=abstract
Astrophysics and Space Science, Volume 29, Issue 1, pp.63-159
Astronomy and Astrophysics
Astrophysics
14
Scientific paper
In this fourth and last part of our analysis, the first section (14) contains a study of the chemical composition of the planets and satellites. A sharp distinction is made between the large quantity of speculations about the interiors of the bodies and the rather meagerfacts known with a reasonable degree of certainty. It is shown, however, that the latter are sufficient todisprove the old concept of a Laplacian disc of homogeneous chemical composition. There is asystematic variations in the chemical composition of planets (and probably also of satellites) so that heavy elements are more abundant in the outermost and in the innermost regions of the systems. Section 15 containsa study of meteorites. These have earlier been interpreted in terms of ‘exploded planets’ and condensation processes in thermodynamic equilibrium. It is shown that such models are irreconcilable with the laws of physics and also with the meteoritic observations. These instead are found toprovide abundant information on the processes in jet streams and on early fractionation and condensation. Further work along these lines supplemented with other solar system materials studies may lead to a detailed reconstruction of important events in the evolution of the solar system. Section 16 demonstrates that the location of the different groups of secondary bodies is a result of a plasma phenomenon occurring at the critical velocity limit. These have recently been studied in detail in the laboratory but have not yet been fully applied to astrophysics.Groups of bodies in the planetary and the satellite systems related by the critical velocity shouldhave the same gravitational potential. There are large chemical differences between groups of different gravitational potential. This is reconcilable with the chemical differentiation found in Section 14. Finally, Section 17 deals with thestructure of the different groups of bodies and shows that the mass distributionis a function of the spin of the central body. Summarizing the properties and distribution of bodies in the solar system against this background, it is shown that there isno need for ‘missing planets’ or to explode hypothetical large bodies. Nor is there any justification for involvingdrastic ad hoc changes in the orbits of existing bodies. The scheme is complete in the sense that in all places where groups of bodies are expected, such bodies are actually found. All of the existing bodies are accounted for (with the exception of the small Martian satellites!). The general conclusion is that already with the empirical material now availableit is possible to suggest a series of basic processes leading to the present structure of planet and satellite systems in an internally consistent way. With the expected flow of data from space research the evolution of the solar system may eventually be described with about the same confidence and accuracy as the geological evolution of the Earth.
Alfvén Hannes
Arrhenius Gustaf
No associations
LandOfFree
Structure and Evolutionary History of the Solar System, IV does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Structure and Evolutionary History of the Solar System, IV, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure and Evolutionary History of the Solar System, IV will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1758436