Small-size dust particles near Halley's comet

Dust-impact PUMA mass-analysers aboard the spacecrafts VEGA-1 and VEGA-2 allow to conduct the first direct measurements of mass-spectra of comet Halley's dust envelope particles with masses higher than 10 −17g /1,2/. The analysis of spectra measured by the PUMA instruments showed that unindentified peaks in this spectra could be associated with very small particles (mass 10 −17- 10 −20g). Detection of small-size particles in the dust envelope of comet Halley agrees with the idea /3/ that the comet's nucleus is an interstellar dust aggregate which contains very small particles.