Chemical abundances determined from meteor spectra — II. Evidence for enlarged sodium abundances in meteoroids

The relative abundances of sodium in meteoroids have been estimated by averaging the composition of the radiating gas along the fireball path produced during their atmospheric entry. We used the method of thermal equilibrium for 13 fireballs produced by meteoroids mainly of cometary origin. The results show greater sodium abundances than those expected for interplanetary dust particles and chondritic meteorites, and interesting differences from the sodium abundance of 1P/Halley comet dust were also found.