Last updated: 20 August 1999


Clark R. Chapman

I originally wrote a long essay, with the above title, in summer 1997 as a draft "Case Study" for a National Science Foundation-sponsored study, organized by the Geological Society of America and the Environmental and Social Impacts Group of the National Center for Atmospheric Research. The project is called Prediction in the Earth Sciences: Use and Misuse in Policy Making. Its goal has been to understand how scientists involved in making "predictions" about future phenomena that can affect society may more effectively communicate with public officials, policy makers, and the public.

This essay went through a number of drafts during the next two years, especially after the infamously erroneous prediction (and resulting media scare) of a significant possibility that asteroid 1997 XF11 could impact the Earth in 2028. A revision dated 7 October 1998 has been at this URL for nearly a year. Subsequently, there have been many additional developments concerning the impact hazard, including interesting cases involving asteroids known as AN10 and OX4. Finally, this document had to be prepared for publication in the "Prediction Science" book, one of the products of the NSF/GSA/NCAR project.

The peer-reviewed document has been rewritten, corrected, and updated once again, in July 1999. However, in order to fit within the chapter page-limits of the book, it was recommended that I delete the lengthy first section of the document, which is a scientific and political history of the impact hazard. Yet this history may be one of the more complete accounts of the development of this now-popular topic. And the October 1998 version of the second part of the text (analysis of the case of 1997 XF11) may still be of interest to some people. So those two parts may still be accessed from the links below. The updated analysis of XF11/AN10/OX4 and resulting policy implications, presented below, is somewhat longer than the version that will eventually appear in the "Prediction Science" book.

Available Abstracts, Preprints, Articles.

Clark R. Chapman's Publications.

Clark R. Chapman's Home Page.

SwRI Boulder Office (GAP) Home Page.

SwRI Home Page