Density and composition of interplanetary dust particles
Abstract
Residual meteoritic material has been detected on the surface of crater interiors on lunar samples 60315,29 and 65315,68. Iron-nickel micrometeoroid residues are present in the form of mettallic spherules embedded in or attached to the crater glass-linings; stony-iron meteorite residual material is homogeneously mixed with the glass-linings. Crater simulation experiments show the dependence of crater diameter to depth ratio on projectile density. On the other hand, the projectile velocities exceeding 4 km/s have no measurable influence on the D/T ratios of microcraters. As a result, diameter-to-depth measurements on lunar microcraters yield three groups of micrometeorites in the size range between 1 μm and 1 mm: iron-nickel, stony-iron and low-density particles. The measured D/T values correspond directly to the kind of determined projectile residues: craters showing residues of iron-nickel meteorites have ratios of D/T = 1.3-1.4 and craters with stony-iron residues have ratios of D/T = 1.9-2.1. Craters with diameters ≲30 μm seem to have been formed predominantly by iron-nickel micrometeorites, whereas craters with diameters ≳80 μm predominantly by stony meteorites.
- Publication:
-
Earth and Planetary Science Letters
- Pub Date:
- May 1976
- DOI:
- 10.1016/0012-821X(76)90250-8
- Bibcode:
- 1976E&PSL..30..234N
- Keywords:
-
- Chemical Composition;
- Craters;
- Interplanetary Dust;
- Lunar Rocks;
- Micrometeoroids;
- Cratering;
- Iron Meteorites;
- Spherules;
- Stony Meteorites;
- Stony-Iron Meteorites