Classification of the Johnson Space Center stratospheric dust collection

Abstract

The NASA Johnson Space Center stratospheric dust collection program has made available to the scientific community a rare set of materials for studies of (1) extraterrestrial materials germane to the early history of the solar system and (2) natural and man‐made terrestrial materials in the stratosphere. A review of the first 291 cataloged particles provides a basis for a reliable taxonomy of all stratospheric particles. Data used in this review include particle shape, size, bulk chemistry, and texture. Extraterrestrial materials occur in all three defined categories: spheres, aggregates, and fragments. Approximately 76% of aggregates are of probable extraterrestrial origin. Spheres contain the least amount of extraterrestrial material (∼43%). A number of new groups of stratospheric particles have been identified. These include aluminum and silicate aggregates, aluminum fragments, and aluminum prime spheres and fragments. Limitations to the use of this classification scheme are based primarily upon the lack of additional data to unambiguously define particle origin.

Possible climatic implications of high-altitude black carbon emissions

“…Moreover, meteoritic debris is reported to be coarse in size (i.e. having a radius larger than 1 µm; Turco et al, 1981;Mackinnon et al, 1982) and hence would have large deposition rates and be largely spherical in shape (Mackinnon et al, 1982) with lower values of particle depolarisation ratio (PDR less than 0.1; Klekociuk et al, 2005). The extinction coefficients associated with plumes of meteoritic debris are 3 orders of magnitude less (Gorkavyi et al, 2013) than the values we notice over our study domain.…”

Dynamic pyrometamorphism during atmospheric entry of large (˜10 micron) pyrrhotite fragments from cluster IDPs

“…The IDPs L2005E40, L2005C39, and L2006A28 were collected on large-area, inertial-impact, flat-plate collectors mounted underneath the wings of a NASA ER-2 aircraft flying over west-central North America, October 3-13, 1989. Mackinnon et al (1982, Warren and Zolensky (1994), and Rietmeijer (1998) reviewed collection and curation procedures.…”

Metastable Eutectic Condensation in a Mg‐Fe‐SiO‐H2‐O2Vapor: Analogs to Circumstellar Dust

“…Since 1974 March interplanetary dust particles (IDPs) have been routinely collected in the EarthÏs lower stratosphere (Brownlee, Tomandl, & Hodge 1976 ;Warren & Zolensky 1994). These particles are a new type of extraterrestrial material that is available for laboratory studies in addition to the meteorites (Mackinnon et al 1982). The mineralogy and texture (Mackinnon & Rietmeijer 1987), and the high carbon (Thomas, Keller, & McKay 1996) and volatile element (Flynn et al 1996) abundances, suggest that the IDPs are the least modiÐed materials in the solar system.…”