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

This global system maintains communications with spacecraft traveling throughout the solar system and beyond, while also supporting radar measurements and radio astronomy research.

From Science Daily ● Oct. 12, 2026

"His tenacity and scientific vision has paved the way for a new kind of astronomy."

From BBC ● Oct. 6, 2026

Belgian particle physicist Francis Halzen was awarded the Nobel Prize in Physics for his contributions to astronomy and his work on the IceCube Neutrino Observatory at the South Pole.

From The Wall Street Journal ● Oct. 6, 2026

He seemed to be an expert at everything, including astronomy, architecture, acting, cars, taxidermy, music, masonry and whales.

From The Wall Street Journal ● Oct. 2, 2026

The five women took classes in astronomy and aeronautics.

From "Women in Space" by Karen Bush Gibson

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Related Words

• astrophysics

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