Preliminary results of the Vega-1 and Vega-2 space probes rendezvous with the Halley comet

Preliminary results of the Halley comet investigation using the Vega-1 and Vega-2 space probes which passed on the 6th and 9th of March, 1986 the comet nucleus at a distance of 9000 and 8200 respectively, are presented. The comet nucleus appeared to be one of the darkest bodies of the Solar system: its albedo is just about 4%. The IR spectrum analysis has shown, that water and carbon dioxide appear to be the main components of the comet material. Mass analysis points out to the presence in the comet dust of iron, oxygen and silicon. It is ascertained, that about 30 t of water vapors and about 5-10 t of dust are evaporated from the comet nucleus surface in one second. Solar wind interaction with the comet streched atmosphere was investigated