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
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The Kuiper Belt begins about 30 astronomical units (AU) from the sun (one AU is the distance of Earth from the sun), its inner edge guarded by Neptune, and extends out to 50 AU.
—
Keith Cooper, Space.com, 30 May 2025
Read More: Our Solar System May Have a New Dwarf Planet Orbiting Even Farther Than Pluto
Crowded Clusters and Far-Flung Planets
Though some planets orbit their stars closely, there are some planets that circle their stars from afar, from hundreds or thousands of astronomical units (AU) away.
—Sam Walters, Discover Magazine, 28 May 2025
The companion's orbit relative to the central star is a bit lopsided, ranging from about two astronomical units (AU, the typical Earth-Sun distance) at its closest approach to roughly three AU at its farthest.
—John Timmer, ArsTechnica, 22 May 2025
The amount of movement on the sky would be tiny — about three arcminutes per year at a distance of approximately 700 astronomical units (AU).
—Keith Cooper, Space.com, 1 May 2025
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Keith Cooper, Space.com, 30 May 2025
Read More: Our Solar System May Have a New Dwarf Planet Orbiting Even Farther Than Pluto
Crowded Clusters and Far-Flung Planets
Though some planets orbit their stars closely, there are some planets that circle their stars from afar, from hundreds or thousands of astronomical units (AU) away.
—Sam Walters, Discover Magazine, 28 May 2025
The companion's orbit relative to the central star is a bit lopsided, ranging from about two astronomical units (AU, the typical Earth-Sun distance) at its closest approach to roughly three AU at its farthest.
—John Timmer, ArsTechnica, 22 May 2025
The amount of movement on the sky would be tiny — about three arcminutes per year at a distance of approximately 700 astronomical units (AU).
—Keith Cooper, Space.com, 1 May 2025
See All Example Sentences for astronomical unit
Cite this Entry
“Astronomical unit.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/astronomical%20unit. Accessed 18 Jun. 2025.
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