DENSITIES OF STRATOSPHERIC MICROMETEORITES

被引：77

作者：

LOVE, SG ^{[1
]}

JOSWIAK, DJ ^{[1
]}

BROWNLEE, DE ^{[1
]}

机构：

[1] UNIV WASHINGTON, DEPT ASTRON, SEATTLE, WA 98195 USA

来源：

ICARUS | 1994年 / 111卷 / 01期

关键词：

D O I：

10.1006/icar.1994.1142

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We have measured the densities of roughly 150 5- to 15-mum interplanetary dust particles harvested in the stratosphere. Care was taken to minimize selection bias in the sample population. Masses were determined using an absolute X-ray analysis technique with a transmission electron microscope, and volumes were found using scanning electron microscope imagery. Unmelted chondritic particles have densities ranging between 0.3 and 6.2 g/cm3, averaging 2.0 g/cm3. The low median density indicates appreciable porosity, suggesting primitive, uncompacted parent bodies for these particles. Porosities greater than about 70% are rare. IDPs with densities above 3.5 g/cm3 usually contain large sulfide grains. We find no evidence of bimodality in the unmelted particle density distribution. Chondritic spherules (melted particles) have densities near 3.4 g/cm3, consistent with previous results for stony spherules culled from deep-sea sediments. (C) 1994 Academic Press, Inc.

引用

页码：227 / 236

页数：10