Discovery of Nucler Tracks in Interplanetary Dust

See allHide authors and affiliations

Science  21 Dec 1984:
Vol. 226, Issue 4681, pp. 1432-1434
DOI: 10.1126/science.226.4681.1432


Nuclear tracks have been identified in interplanetary dust particles (IDP's) collected from the stratosphere. The presence of tracks unambiguously confirms the extraterrestrial nature of IDP's, and the high track densities (1010 to 1011 per square centimeter) suggest an exposure age of approximately 104 years within the inner solar system. Tracks also provide an upper temperature limit for the heating of IDP's during atmospheric entry, thereby making it possible to distinguish between pristine and thermally modified micrometeorites.