A search for airborne particles of meteoritic origin
Abstract
A year-long programme involving daily collections of atmospheric dust at several widely separated, isolated sites has been undertaken with the object of identifying particles that may be of extraterrestrial origin. The particles in question are opaque, shiny spherules with diameters less than 15 μ. They appear to be of a nature entirely different from that of the larger spheres abounding in densely populated areas. Their meteoritic origin is suggested by recent evidence regarding ablation of meteorites and by the fact that the rate of fall and the frequency distribution with size of these particles have been found to be the same at the various stations. The average rate of fall for each station was 1·1 spherules greater than 3 μ in diameter/cm 2/day. Assuming that the density of the counted particles is that of magnetite, this rate corresponds to an annual accretion for the entire earth of about 5 × 10 8 kg of these particles.
- Publication:
-
Geochimica et Cosmochimica Acta
- Pub Date:
- August 1958
- DOI:
- 10.1016/0016-7037(58)90101-7
- Bibcode:
- 1958GeCoA..14..126H