astronomy

noun as·tron·o·my \ ə-ˈsträ-nə-mē \

Updated on: 17 Apr 2018

Definition of astronomy

plural astronomies

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

See astronomy defined for English-language learners

See astronomy defined for kids

Recent Examples of astronomy from the Web

Mullaly just left astronomy to work at an image-analysis company called Orbital Insight.

— sarah scoles, WIRED, "The Case of the Evaporating Exoplanets," 12 Apr. 2018
Fallout from problems with the space telescope, the largest space science program in U.S. history, could adversely affect other U.S. and international astrophysics and astronomy projects.

— andy pasztor, WSJ, "Northrop Grumman Revises Satellite Procedures After Telescope Delay," 30 Mar. 2018
Pieter van Dokkum, an astronomy and physics professor at Yale University and the lead author of the Nature study, tells The Verge.

— loren grush, The Verge, "Rare galaxy found without any dark matter," 28 Mar. 2018
Davide Castelvecchi Davide Castelvecchi is a senior reporter at Nature in London covering physics, astronomy, mathematics and computer science.

— davide castelvecchi, Scientific American, "“Grand Unified Theory of Math” Nets Abel Prize," 20 Mar. 2018
Hotels in the area take advantage of the evening bounty with events like the Night Sky astronomy and bonfire series at Grand Velas, private stargazing tours at the uber luxe One & Only Palmilla, and the Hotel Ganzo’s full moon yoga sessions.

— stephanie granada, Sunset, "10 Stellar Places for Stargazing," 22 Jan. 2018
As an undergrad at Harvard, McCargar had started out majoring in physics and astronomy, but while hitchhiking across the country one summer he’d got caught up in the environmental movement and switched to biology.

— naomi fry, The New Yorker, "Scott Pruitt’s Dirty Politics," 3 Apr. 2017
But this three-bedroom house, designed for two astronomy photographers and positioned to face the magnetic north like the needle of a compass, is a point of convergence.

— latimes.com, "Today: Russia, the Slapdown and the Silence," 27 Mar. 2018
Retrograde motion is not new to astrology or astronomy.

— wilder davies, Time, "Mercury Is Entering Retrograde Again. This Is Why So Many People Care," 22 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'astronomy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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.

Origin and Etymology of astronomy

Middle English astronomie, from Anglo-French, from Latin astronomia, from Greek, from astr- + -nomia -nomy

NEW! Time Traveler

First Known Use: 12th century

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Other Astronomy Terms

gibbous, nadir, nebulous, penumbra, retrograde, sidereal, syzygy, wane, wax, zenith

ASTRONOMY Defined for English Language Learners

astronomy

noun

Definition of astronomy for English Language Learners

: the scientific study of stars, planets, and other objects in outer space

ASTRONOMY Defined for Kids

astronomy

noun as·tron·o·my \ ə-ˈsträ-nə-mē \

Definition of astronomy for Students

: a science concerned with objects and matter outside the earth's atmosphere and of their motions and makeup

Learn More about astronomy

See words that rhyme with astronomy Spanish Central: Translation of astronomy Nglish: Translation of astronomy for Spanish speakers Britannica English: Translation of astronomy for Arabic speakers Britannica.com: Encyclopedia article about astronomy

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astronomy

Definition of astronomy

Recent Examples of astronomy from the Web

The Difference Between astronomy and astrology

Origin and Etymology of astronomy

Other Astronomy Terms

ASTRONOMY Defined for English Language Learners

astronomy

Definition of astronomy for English Language Learners

ASTRONOMY Defined for Kids

astronomy

Definition of astronomy for Students

Learn More about astronomy

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astronomy

Definition of astronomy for Students

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