The return of Halley's Cornet in 1986 has generated much ex citement in the scientific community with preparations already afoot for an International Cornet Watch and a cornet launch by the European Space Community, the Japanese and Soviet Space Scientists. The meet ing held at the University of Maryland in October 1980 was primarily stimulated by the preparations for further study of this cornet and by one of the most important unanswered questions related to comets, name ly, whether they may have made a eontribution to the origin of life on earth. Our un"derstanding of the role of comets in...

The return of Halley's Cornet in 1986 has generated much ex citement in the scientific community with preparations already afoot for an International Cornet Watch and a cornet launch by the European Space Community, the Japanese and Soviet Space Scientists. The meet ing held at the University of Maryland in October 1980 was primarily stimulated by the preparations for further study of this cornet and by one of the most important unanswered questions related to comets, name ly, whether they may have made a eontribution to the origin of life on earth. Our un"derstanding of the role of comets in...

This volume is the fourth in the series of the Proceedings of the College Park Colloquia on Chemical Evolution. These Colloquia, and the resulting Proceedings, are presented in the interest of fostering the impact of the interdisciplinary nature of chemical evolu tion on contemporary scientific thought. vii EDITORS'INTRODUCTION The Fourth College Park Colloquium on Chemical Evolution was held on October 18 - 20, 1978 at the University of Maryland. The meeting, supported by the National Aero nautics and Space Administration and the National Science Foundation, centered on the variable...