"TITLE","AUTHORS","SUBJECT","SUBJECT_RELATED","DESCRIPTION","PUBLISHER","AVAILABILITY","RESEARCH_ORG","SPONSORING_ORG","PUBLICATION_COUNTRY","PUBLICATION_DATE","CONTRIBUTING_ORGS","LANGUAGE","RESOURCE_TYPE","TYPE_QUALIFIER","JOURNAL_ISSUE","JOURNAL_VOLUME","RELATION","COVERAGE","FORMAT","IDENTIFIER","REPORT_NUMBER","DOE_CONTRACT_NUMBER","OTHER_IDENTIFIER","DOI","RIGHTS","ENTRY_DATE","OSTI_IDENTIFIER","PURL_URL" "Detection of /sup 4/He in stratospheric particles gives evidence of extraterrestrial origin","Rajan, R S [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism]; Brownlee, D E; Tomandl, D; Hodge, P W; Farrar, H; Britten, R A","71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; METEOROIDS; CHEMICAL COMPOSITION; ABUNDANCE; HELIUM 4; MASS SPECTROSCOPY; METEORITES; PARTICLE SIZE; SOLAR WIND; STRATOSPHERE; EARTH ATMOSPHERE; EVEN-EVEN NUCLEI; HELIUM ISOTOPES; ISOTOPES; LIGHT NUCLEI; NUCLEI; SIZE; SOLAR ACTIVITY; SPECTROSCOPY; STABLE ISOTOPES; 640107* - Astrophysics & Cosmology- Planetary Phenomena","","The detection of large concentrations of /sup 4/He in some ..mu..m size stratospheric particles collected during the past 2 years is here reported. The final /sup 4/He concentrations ranged from 0.002 to 0.25 cc/gm. Such high concentrations confirm that the particles were extraterrestrial and that some of them were exposed to solar wind for at least 10 to 100 years; also, since solar wind ions are implanted only to depths of approximately 500 A, the measurements also indicate that the particles existed as small particles in space and were not produced in the atmosphere by fragmentation of larger meteoroids. The possibility that the observed He could have been the product of decaying U appears remote. Since micrometeorites probably have cometary origin, they are potentially a valuable source of primitive Solar System matter.","","","","","United Kingdom","1977-05-12","","English","Journal Article","","","267:5607","Journal Name: Nature (London); (United Kingdom); Journal Volume: 267:5607","","Medium: X; Size: Pages: 133-134","","","","Journal ID: CODEN: NATUA","https://doi.org/10.1038/267133a0","","2010-12-29","5442038",""