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

The celestial phenomenon is said to be a beautiful sight, but will astronomy lovers and visitors to Kentucky actually be able to see it? —Marina Johnson, The Courier-Journal, 4 Apr. 2024

So there's going to be a lot of astronomy and science, which is great for nerds like me who love that. —Dana Taylor, USA TODAY, 29 Mar. 2024

In addition to being a highly respected educator, renowned for his deep knowledge of astronomy from both an Indigenous and a Western approach, Buck is an elder and ceremonial leader for the Cree, one of Canada’s largest First Nations groups. —Lise Pedersen, Variety, 15 Mar. 2024

Solar eclipses may strike awe or even fear in people, especially those less versed in astronomy. —Joshua Rapp Learn, Discover Magazine, 11 Mar. 2024

Hamber spent his career as a physicist, teaching physics and astronomy at the University of California, Irvine. —USA TODAY, 21 Mar. 2024

The books go into a lot of detail about particle accelerators and computer programming and astronomy. —Amit Katwala, WIRED, 21 Mar. 2024

Elsewhere, millimeter waves are used for many purposes, including 5G wireless networks, airport security, and astronomy. —IEEE Spectrum, 12 Mar. 2024

And the group marathons hosted by local astronomy clubs in March are friendly to newcomers. —Carlyn Kranking, Smithsonian Magazine, 7 Mar. 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