Library cataloging
and classification
main topicastronomy
ColonB9 Edit this on Wikidata
Dewey Decimal520 Edit this on Wikidata
Library of CongressQB Edit this on Wikidata
Universal Decimal52 Edit this on Wikidata

Astronomy is a science involving the observation and explanation of events occurring outside Earth and its atmosphere. It includes the study of the origin, evolution, and physical and chemical properties of objects that can be observed in the sky, space, and in the whole universe.