astronomical unit

noun

: a unit of length used in astronomy equal to the mean distance of the earth from the sun or about 93 million miles (150 million kilometers)

Examples of astronomical unit in a Sentence

Recent Examples on the Web Based on their models, its reach would have shrunk to 0.22 astronomical units—or just about a fifth of the distance between the Earth and sun—leaving our planet outside the star’s protective field. Christian Thorsberg, Smithsonian Magazine, 14 June 2024 It's probably located somewhere between 500 and 600 astronomical units from the Sun. Chas Newkey-Burden, The Week Uk, theweek, 19 Apr. 2024 At its orbital distance of 1 astronomical unit from the sun, Earth receives about 1.4 kilowatts per square meter from sunlight. Karl Schroeder, IEEE Spectrum, 24 Feb. 2024 And the light emission during the dimming suggests that the material can't be more than 16 astronomical units out. John Timmer, Ars Technica, 11 Oct. 2023 See all Example Sentences for astronomical unit 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'astronomical unit.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1848, in the meaning defined above

Time Traveler
The first known use of astronomical unit was in 1848

Dictionary Entries Near astronomical unit

Cite this Entry

“Astronomical unit.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronomical%20unit. Accessed 25 Jul. 2024.

Kids Definition

astronomical unit

noun
: a unit of length used in astronomy equal to the average distance of the earth from the sun or about 93 million miles (150 million kilometers)

More from Merriam-Webster on astronomical unit

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