Letters Killer Asteroid Twin? + See all authors and affiliations Science 09 Jul 1993:Vol. 261, Issue 5118, pp. 146DOI: 10.1126/science.261.5118.146-b Paul T. WilsonFind this author on Google Scholar Find this author on PubMed Search for this author on this site Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears below.