: the study of objects and matter outside the earth's atmosphere and of their physical and chemical properties
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The Difference Between Astronomy and Astrology
Some may find it easy to confuse astronomy and astrology. At one time, these two words actually were synonymous (that is, astronomy once meant what astrology means today), but they have since moved apart from each other. In current use, astronomy is concerned with "the study of objects and matter outside the earth's atmosphere," while astrology is the purported divination of how stars and planets influence our lives. Put bluntly, astronomy is a science, and astrology is not.
Examples of astronomy in a Sentence
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Spectacle is hard to make compelling in writing; so are long speeches about religion or astronomy.—Claudia Roth Pierpont, New Yorker, 24 Nov. 2025 Some of the earliest respect for the power of observation comes from the ancient Indus Valley, where close astronomical observations and unit measurements were required for ritual, and these traditions bore fruit in early treatises on astronomy, linguistics, and logic.—Literary Hub, 19 Nov. 2025 Most astronomy books provide various versions of this story, and yet, rarely is Pegasus ever mentioned in Perseus' other adventures.—Joe Rao, Space.com, 16 Nov. 2025 That’s a metal, too, as far as astronomy is concerned.—Phil Plait, Scientific American, 13 Nov. 2025 See All Example Sentences for astronomy
Word History
Etymology
Middle English astronomie "study of celestial bodies, including their possible influence on human affairs," borrowed from Anglo-French & Latin; Anglo-French astronomie, borrowed from Latin astronomia, borrowed from Greek astronomía "study of the stars, especially their movements," from astro-astro- + -nomia-nomy
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