plan·e·tar·i·um /ˌplænəˈtɛriəm/
  行星儀,天文
  Plan·e·ta·ri·um n.  An orrery. See Orrery.
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  planetarium
       n 1: a building housing an instrument for projecting the
            positions of the planets onto a domed ceiling
       2: an optical device for projecting images of celestial bodies
          and other astronomical phenomena onto the inner surface of
          a hemispherical dome
       3: an apparatus or model for representing the solar systems
       [also: planetaria (pl)]