mega·​par·​sec | \ ˌme-gə-ˈpär-ˌsek How to pronounce megaparsec (audio) \

Definition of megaparsec

: a unit of measure for distances in intergalactic space equal to one million parsecs

Examples of megaparsec in a Sentence

Recent Examples on the Web

Planck's data pegs the Hubble constant at about 67.4 kilometers per second per megaparsec, give or take 0.5. National Geographic, "The universe seems to be expanding faster than all expectations," 25 Apr. 2019 This was a gross overestimate; by the 1970s, astrophysicists favored values for the Hubble constant around either 50 or 100 kilometers per second per megaparsec, depending on their methods. Quanta Magazine, "Colliding Neutron Stars Could Settle the Biggest Debate in Cosmology," 25 Oct. 2017 According to the cosmic ladder, the universe is expanding at a rate of 73.24km per second per megaparsec. The Economist, "The two ways to measure how fast the universe is growing do not agree," 17 May 2018 According to supernovae and Cepheids, the universe is expanding at a rate of 73.5 kilometers per second per megaparsec (about 3.3 million light-years). Lee Billings, Scientific American, "Cosmic Conflict: Diverging Data on Universe’s Expansion Polarizes Scientists," 16 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'megaparsec.' 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 megaparsec

1920, in the meaning defined above

History and Etymology for megaparsec

mega- + parsec

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Statistics for megaparsec

Last Updated

29 Jun 2019

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Time Traveler for megaparsec

The first known use of megaparsec was in 1920

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More from Merriam-Webster on megaparsec

Rhyming Dictionary: Words that rhyme with megaparsec Encyclopedia article about megaparsec

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