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Hubble, Edwin Powell

(Encyclopedia)Hubble, Edwin Powell, 1889–1953, American astronomer, b. Marshfield, Mo. He did research (1914–17) at Yerkes Observatory, and joined (1919) the staff of Mt. Wilson Observatory, Pasadena, Calif., o...

Mars, family of American food manufacturers

(Encyclopedia)Mars, family of American food manufacturers. Franklin Clarence Mars, 1882–1934, b. Hancock, Minn., was a chocolate manufacturer who produced candy at home before opening a candy factory (1911) in Ta...

gamma-ray astronomy

(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...

Magellanic Clouds

(Encyclopedia)Magellanic Clouds măjˌəlănˈĭk [key], two dwarf galaxies located in the far southern sky and visible to the unaided eye; they are classified as irregular because they show no definite symmetry or...

moonstone

(Encyclopedia)moonstone, an orthoclase feldspar, found in Sri Lanka, Myanmar, and Madagascar (and formerly in the St. Gotthard district of Switzerland). In spite of its pronounced cleavage, it is widely used as a g...

ammoniac

(Encyclopedia)ammoniac or gum ammoniac əmōˈnēăkˌ [key], yellowish substance with a sickening, bitter taste, obtained from the milky exudate of the injured stem of a plant (Dorema ammoniacum) found in Iran, In...

quasar

(Encyclopedia)quasar kwāˈsär [key], one of a class of blue celestial objects having the appearance of stars when viewed through a telescope and currently believed to be the most distant and most luminous objects...

red shift

(Encyclopedia)red shift or redshift, in astronomy, the systematic displacement of individual lines in the spectrum of a celestial object toward the red, or longer wavelength, end of the visible spectrum. The effect...

feldspar

(Encyclopedia)feldspar fĕlˈspär [key], an abundant group of rock-forming minerals which constitute 60% of the earth's crust. Chemically the feldspars are silicates of aluminum, containing sodium, potassium, iron...

planetarium

(Encyclopedia)planetarium, optical device used to project a representation of the heavens onto a domed ceiling; the term also designates the building that houses such a device. A modern planetarium consists of as m...