The Planets Their Origin And Development

This is a study based on observation rather than mathematical theory in which an attempt is made to discover facts and relationships that give evidence about the course of solar evolution. The author's principle conclusions are that the earth and other territorial planets were formed at much lower temperatures than has generally been supposed; and that a more uniform distribution of iron throughout the silicate phases of the Earth existed in the past than exist now while the iron core of the Earth has been formed at least partly during geological time. For convenience of discussion the author divides the course of planetary evolution into five stages: stage 1 is assumed to start with an interstellar dust cloud, such as the globes of Bok and Reill; stage 2 he calls the preprotoplanet and protoplanet phase, when temperatures had risen to their present levels; stage 3 is the "high temperature stage", and stage 4 is the second low temperature stage; in his final stage the author outlines possible origins for the atmospheres of the earth, Venus and Mars. It may at first surprise that a physical chemist should write a book on the origin and development of the planets. But as the physical problems are many and involved and as the evidence in regard to them is very detailed, the physical chemist can obviously make valuable contributions to this subject. Mr Urey has discussed his views with astronomers, physicists, geophysicists and many other experts and frequently made use of their critical appreciation.

This work is addressed to advanced undergraduate and graduate students in astronomy, geology, chemistry, meteorology, and the planetary sciences as well as to researchers with pertinent areas of specialization who desire an introduction to the literature across the broad interdisciplinary range of this important topic. Extensive references to the pre-spacecraft literature will be particularly useful to readers interested in the historical development of the field during this century.

The age-old question of how our home planet and its satellite originated has in recent times undergone a minor revolution. The emergence of the "giant impact theory" as the most successful model for the origin of the Moon has been difficult to reconcile with some aspects of the Earth, and the development of an integrated model for the origin of the Earth-Moon system has been difficult for this reason. However, recent technical advances in experimental and isotopic work, together with intensified interest in the modeling of planetary dynamics, have produced a wealth of new results requiring a rethinking of models for the origin of the Earth and Moon. This book is intended to serve as a resource for those scientists working closely in this field, while at the same time it provides enough balance and depth to offer an introduction for students or technically minded general readers. Its thirty chapters address isotopic and chemical constraints on accretion, the dynamics of terrestrial planet formation, the impact-triggered formation of the Earth-Moon system, differentiation of the Earth and Moon, the origin of terrestrial volatiles, and conditions on the young Earth and Moon. Covering such subjects as the history and origin of the Moon's orbit, water on the Earth, and the implications of Earth-Moon interactions for terrestrial climate and life, the book constitutes a state-of-the-art overview of the most recent investigations in the field. Although many advances have been made in our ability to evaluate competing models of the formation of the Earth-Moon system, there are still many gaps in our understanding. This book makes great strides toward closing those gaps by highlighting the extensive progress that has been made and pointing toward future research.

This fully-updated second edition remains the only truly detailed exploration of the origins of our Solar System, written by an authority in the field. Unlike other authors, Michael Woolfson focuses on the formation of the solar system, engaging the reader in an intelligent yet accessible discussion of the development of ideas about how the Solar System formed from ancient times to the present.Within the last five decades new observations and new theoretical advances have transformed the way scientists think about the problem of finding a plausible theory. Spacecraft and landers have explored the planets of the Solar System, observations have been made of Solar-System bodies outside the region of the planets and planets have been detected and observed around many solar-type stars. This new edition brings in the most recent discoveries, including the establishment of dwarf planets and challenges to the ‘standard model’ of planet formation — the Solar Nebula Theory.While presenting the most up-to-date material and the underlying science of the theories described, the book avoids technical jargon and terminology. It thus remains a digestible read for the non-expert interested reader, whilst being detailed and comprehensive enough to be used as an undergraduate physics and astronomy textbook, where the formation of the solar system is a key part of the course.Michael Woolfson is Emeritus Professor of Theoretical Physics at University of York and is an award-winning crystallographer and astronomer.