Pieces of a fluffy comet.Pieces of a fluffy fluff·y adj. fluff·i·er, fluff·i·est 1. a. Of, relating to, or resembling fluff. b. Covered with fluff. 2. Light and airy; soft: fluffy curls; a fluffy soufflé. comet Measurements during spacecraft encounters with Comet Halley (SN: 5/24/86, p.327) revealed that dust shed by the comet contained elements such as hydrogen, carbon, oxygen, silicon and magnesium. Those observations indicate the dust particles probably consist largely of water ice, silicates and various hydrocarbons. J. Mayo Greenberg of the University of Leiden in the Netherlands suggests these materials are layered within tiny, capsule-like grains. Each grain has a silicate silicate, chemical compound containing silicon, oxygen, and one or more metals, e.g., aluminum, barium, beryllium, calcium, iron, magnesium, manganese, potassium, sodium, or zirconium. Silicates may be considered chemically as salts of the various silicic acids. core, surrounded by an inner mantle of hydrocarbon material and an outer mantle of ice flecked fleck n. 1. A tiny mark or spot: flecks of mica in the rock. 2. A small bit or flake: flecks of foam; a fleck of dandruff. tr.v. with minute, dark particles. Hundreds of these grains stick together to form a single dust particle, producing a fluffy aggregate, about 80 percent empty space, with an average diameter of 5 microns. "Such a model would explain practically all that we observed in the dust of [Comet] Halley," says vassily I. Moroz of the Space Research Institute of the USSR USSR: see Union of Soviet Socialist Republics. in Moscow. Whether the dust from Comet Halley is typical of interstellar in·ter·stel·lar adj. Between or among the stars: interstellar gases. interstellar Adjective between or among stars Adj. 1. dust is unknown. Researchers have proposed a number of alternative models for interstellar dust (SN: 6/18/88, p.396). |
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