plan·​e·​tar·​i·​um | \ˌpla-nə-ˈter-ē-əm \
plural planetariums or planetaria\ ˌpla-​nə-​ˈter-​ē-​ə \

Definition of planetarium 

1 : a model or representation of the solar system

2a : an optical device for projecting various celestial images and effects

b : a building or room housing such a projector

Examples of planetarium in a Sentence

Recent Examples on the Web

When Tech Meets Art, futurism discussion; Cool Neon, programmable LED talk/exhibit; extended aquarium/exhibition hours; Incoming, planetarium showing; cocktails. Chronicle Staff Report, San Francisco Chronicle, "Exhibits listings," 26 Apr. 2018 Ben Coughenour, planetarium coordinator at Wayne State University, said Detroit will not be able to see the total eclipse, as the moon will set at 7:46 a.m. and the total eclipse begins at 7:51. Omar Abdel-baqui, Detroit Free Press, "Lunar eclipse, supermoon and blue moon: Don't miss it Wednesday," 27 Jan. 2018 This year, in Tunisia, there will be a full day of programming at the planetarium in Tunis. New York Times, "Letter of Recommendation: Asteroid Day," 20 June 2018 On the same day, people will be able to take virtual tours of the universe at UofL's portable planetarium from 9 a.m.-2 p.m. The fairgrounds is located at 937 Phillips Lane. Darla Carter, The Courier-Journal, "10 Louisville spots offering free eclipse glasses on Monday," 16 Aug. 2017 Now known as the Daniel M. Soref Dome Theater & Planetarium, the facility is, more or less, back to the original idea: a planetarium. Chris Foran, Milwaukee Journal Sentinel, "Milwaukee once tried to launch its own space center. It never took off.," 12 June 2018 During the day, the planetarium still holds traditional space science shows on the solar system, NASA missions, and the night sky. Cristela Guerra,, "At the planetarium, drag shows that are out of this world," 23 June 2018 The planetarium is scheduled to be erected again this year, librarians said. Pioneer Press,, "Tomes aren't the only offerings at local public libraries: Officials," 4 May 2018 With Push the Feeling DJs; pop-up beer garden; extended aquarium/exhibition hours; The Plant Ladym and Sutro Stewards, plant talks; planetarium screening; cocktails., "Exhibits listings," 12 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'planetarium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of planetarium

1860, in the meaning defined at sense 1

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Last Updated

6 Nov 2018

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Time Traveler for planetarium

The first known use of planetarium was in 1860

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English Language Learners Definition of planetarium

: a building or room in which images of stars, planets, etc., are shown on a high, curved ceiling


plan·​e·​tar·​i·​um | \ˌpla-nə-ˈter-ē-əm \

Kids Definition of planetarium

: a building in which there is a device for projecting the images of heavenly bodies on a ceiling shaped like a dome

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