[plan-i-tair-ee-uh m] /ˌplæn ɪˈtɛər i əm/
noun, plural planetariums, planetaria
[plan-i-tair-ee-uh] /ˌplæn ɪˈtɛər i ə/ (Show IPA)
an apparatus or model representing the planetary system.
a device that produces a representation of the heavens by the use of a number of moving projectors.
the building or room in which such a device is housed.
noun (pl) -iums, -ia (-ɪə)
an instrument for simulating the apparent motions of the sun, moon, and planets against a background of stars by projecting images of these bodies onto the inside of a domed ceiling
a building in which such an instrument is housed
a model of the solar system, sometimes mechanized to show the relative motions of the planets
1734, “orrery,” Modern Latin, from Late Latin planeta (see planet) + Latin -arium “a place for.” Sense of “device for projecting the night sky onto the interior of a dome” is attested from 1929.
[plan-i-ter-ee] /ˈplæn ɪˌtɛr i/ adjective 1. of, relating to, or resembling a or the . 2. wandering; erratic. 3. terrestrial; global. 4. Machinery. noting or pertaining to an epicyclic gear train in which a sun gear is linked to one or more gears also engaging with an encircling ring gear. noun 5. Machinery. a planetary […]
noun, Astronomy. 1. an expanding shell of thin ionized gas that is ejected from and surrounds a hot, dying star of about the same mass as the sun; the gas absorbs ultraviolet radiation from the central star and reemits it as visible light by the process of fluorescence. noun 1. an expanding shell of gas […]
noun, Astronomy. 1. the small component of the precession of the equinoxes contributed by the motion of the ecliptic, the change in orientation of the plane of the earth’s orbit being produced by the gravitational attraction of the planets.
[plan-i-tes-uh-muh l] /ˌplæn ɪˈtɛs ə məl/ Astronomy noun 1. one of the small celestial bodies that, according to one theory (planetesimal hypothesis) were fused together to form the of the solar system. adjective 2. of or relating to a planetesimal or planetesimals. planetesimal (plān’ĭ-těs’ə-məl) Any of innumerable small bodies of accreted gas and dust thought […]