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

That's when the moon won't interfere with the display and the Taurus constellation, which is where the meteors seem to emerge – or radiate, according to Earth Sky, a website devoted to astronomy and Earth sciences. —Eric Lagatta, USA TODAY, 4 Nov. 2024

Check my main feed for more in-depth articles on stargazing, astronomy, eclipses and more. —Jamie Carter, Forbes, 4 Nov. 2024

Lee Billings is a science journalist specializing in astronomy, physics, planetary science, and spaceflight, and is a senior editor at Scientific American. —Lee Billings, Scientific American, 21 Oct. 2024

The board had just sworn in its newest members, including an astronomy professor from the University of California, Los Angeles, named Ben Zuckerman. —Abrahm Lustgarten, ProPublica, 19 Oct. 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