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

See stars, planets Hobbs State Park-Conservation Area will host a free astronomy program from 5:30 to 8:30 p.m. Saturday at the park visitor center. —Flip Putthoff, arkansasonline.com, 29 Oct. 2024

Introduction By Jonathan O'Callaghan Contributing Writer October 23, 2024 astronomy astrophysics black holes dark matter galaxies gravitational waves physics All topics (opens a new tab) Galaxies have been merging into ever-bigger structures over the course of cosmic history. —Quanta Magazine, 23 Oct. 2024

In April 2021, astronomy educator John Heasley set out to see just how dark the skies were in southwestern Wisconsin's Vernon County. —Madeline Heim, Journal Sentinel, 8 Oct. 2024

This is the ideal purchase for astronomy enthusiasts. —Margaret Drake, Rolling Stone, 22 Sep. 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