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Dark Nebulae
A dark nebula or absorption nebula is a type of interstellar cloud, particularly molecular clouds, that is so dense that it obscures the Visible spectrum, visible wavelengths of light from objects behind it, such as background stars and emission nebula, emission or reflection nebula, reflection nebulae. The extinction (astronomy), extinction of the light is caused by cosmic dust, interstellar dust grains in the coldest, densest parts of molecular clouds. Clusters and large complexes of dark nebulae are associated with Giant Molecular Clouds. Isolated small dark nebulae are called Bok globules. Like other interstellar dust or material, the things it obscures are visible only using radio waves in radio astronomy or infrared in infrared astronomy. Dark clouds appear so because of sub-micrometre-sized dust particles, coated with frozen carbon monoxide and nitrogen, which effectively block the passage of light at visible wavelengths. Also present are molecular hydrogen, atomic helium, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
All Quiet In The Nursery?
All or ALL may refer to: عرص Biology and medicine * Acute lymphoblastic leukemia, a cancer * Anterolateral ligament, a ligament in the knee * ''All.'', taxonomic author abbreviation for Carlo Allioni (1728–1804), Italian physician and professor of botany Language * All, an indefinite pronoun in English * All, one of the English determiners * Allar language of Kerala, India (ISO 639-3 code) * Allative case (abbreviated ALL) Music * All (band), an American punk rock band ** All (All album), ''All'' (All album), 1999 * All (Descendents album), ''All'' (Descendents album) or the title song, 1987 * All (Horace Silver album), ''All'' (Horace Silver album) or the title song, 1972 * All (Yann Tiersen album), ''All'' (Yann Tiersen album), 2019 * All (song), "All" (song), by Patricia Bredin, representing the UK at Eurovision 1957 * "All (I Ever Want)", a song by Alexander Klaws, 2005 * "All", a song by Collective Soul from ''Hints Allegations and Things Left Unsaid'', 1994 Sports * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
