astronomy

American  

[uh-stron-uh-mee] / əˈstrɒn ə mi /

noun

1. 

   the science that deals with the material universe beyond the earth's atmosphere.

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astronomy British  

/ əˈstrɒnəmɪ /

noun

1. the scientific study of the individual celestial bodies (excluding the earth) and of the universe as a whole. Its various branches include astrometry, astrodynamics, cosmology, and astrophysics

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astronomy Scientific  

/ ə-strŏn′ə-mē /

1. The scientific study of the universe and the objects in it, including stars, planets, nebulae, and galaxies. Astronomy deals with the position, size, motion, composition, energy, and evolution of celestial objects. Astronomers analyze not only visible light but also radio waves, x-rays, and other ranges of radiation that come from sources outside the Earth's atmosphere.

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astronomy Cultural  

1. The science that deals with the universe beyond the Earth. It describes the nature, position, and motion of the stars, planets, and other objects in the skies, and their relation to the Earth.

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Etymology

Origin of astronomy

First recorded in 1175–1225; Middle English astronomie, from Anglo-French, from Latin astronomia, from Greek; equivalent to astro- + -nomy

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Compare meaning

How does astronomy compare to similar and commonly confused words? Explore the most common comparisons:

• astronomy vs. astrology

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Explanation

Astronomy is the science that looks up: at stars, at other planets, at solar systems, at galaxies, and at everything else in the universe. The Ancient Greeks used the word astron for "star," so it only makes sense that astronomy would involve the study or the stars (and other unearthly topics). Someone who studies or works in astronomy is an astronomer, and one of the main tools of the trade is the telescope. As telescopes get more and more powerful, astronomers learn more and more about what's going on out there, such as how old a star or planet is. If you ever wondered what's out there besides the Earth, you should learn more about astronomy.

Example Sentences

See Examples For:

astronomy

It hires gig workers in fields as far-flung as astronomy, creative writing, law and investment banking.

From The Wall Street Journal ● Oct. 17, 2026

There are about 80 events taking place across the park, from moonlit swimming and astronomy sessions, to bioluminescence walks and planetarium shows.

From BBC ● Oct. 16, 2026

Australia's radio astronomy facilities have a long history of supporting some of NASA's most important space missions.

From Science Daily ● Oct. 12, 2026

He said the "trigger moment" for his lifelong interest in astronomy was seeing the Milky Way in the night sky when he was 10.

From BBC ● Oct. 11, 2026

There had been stable, consensus-based sciences before: Ptolemaic astronomy, for example, or Vesalian anatomy.

From "The Invention of Science" by David Wootton

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Related Words

• astrophysics

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