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 In their analysis, H0 comes out to be 73.04 ± 1.04 kilometers per second per megaparsec. Anil Ananthaswamy, Scientific American, 18 Apr. 2022 Each number is an expression of the same thing—the kilometers-per-second rate of cosmic expansion per every megaparsec (roughly 3.26 million light-years) of space. Daniel Leonard, Scientific American, 25 Jan. 2022 The trend continued; as of their latest analysis last March, Riess’s team pegged the Hubble constant at 74 kilometers per second per megaparsec, 9% higher than the 67.4 extrapolated from the early universe. Quanta Magazine, 26 Feb. 2020 Under certain assumptions about the fundamental nature of the universe, Planck data suggest that the Hubble constant should have a value of 67.4 kilometers a second per megaparsec, give or take 0.5. Michael Greshko, National Geographic, 12 Sep. 2019 The Planck team predicts that the universe should expand at a rate of 67.4 kilometers per second per megaparsec. Quanta Magazine, 8 Aug. 2019 These ripples can be mapped and modeled to predict the expansion rate, which placed it at 67.4 kilometers per second per megaparsec. Ashley Strickland, CNN, 16 July 2019 Planck's data pegs the Hubble constant at about 67.4 kilometers per second per megaparsec, give or take 0.5. National Geographic, 25 Apr. 2019 According to the cosmic ladder, the universe is expanding at a rate of 73.24km per second per megaparsec. The Economist, 17 May 2018 See More

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.

First Known Use of megaparsec

1920, in the meaning defined above

History and Etymology for megaparsec

mega- + parsec

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The first known use of megaparsec was in 1920

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Last Updated

24 Apr 2022

Cite this Entry

“Megaparsec.” Dictionary, Merriam-Webster, Accessed 28 May. 2022.

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