astronomy

noun

as·​tron·​o·​my ə-ˈsträ-nə-mē 

plural astronomies

: the study of objects and matter outside the earth's atmosphere and of their physical and chemical properties

Did you know?

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

Recent Examples on the Web

Tammin Sursok stars as an astronomy professor who butts heads with Brant Daugherty, a football coach who cuts in the faculty buffet line but also has to join her trivia team. —Vanessa Franko, Los Angeles Times, 18 Dec. 2024

Before modern astronomy, solar eclipses were often assigned mythological or theological significance, which likely contributed to our enduring fascination with them. —Rafi Schwartz, The Week Us, theweek, 16 Dec. 2024

Particular attention in the exhibition is also given to the Umayyads’ contributions to science and technology through the display of sundials that were used in early Islamic astronomy. —Chadd Scott, Forbes, 12 Dec. 2024

But the era of digital astronomy, where astronomical images are recorded on computers and saved in databases, is very recent – only since the year 2000 or so. —Jonathan Zrake, Discover Magazine, 5 Dec. 2024

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

First Known Use

12th century, in the meaning defined above

Phrases Containing astronomy

• radar astronomy
• radio astronomy
• X-ray astronomy

Kids Definition

astronomy

noun

as·​tron·​o·​my ə-ˈsträn-ə-mē 

plural astronomies

: the science of the heavenly bodies and of their sizes, motions, and composition

astronomer

-mər

noun