"Astronomy is a natural science that studies celestial objects and phenomena."
The study of celestial objects, their behavior, and their relationships with each other.
"In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars."
"Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets."
"Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation."
"Cosmology is a branch of astronomy that studies the universe as a whole."
"The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptians, Babylonians, Greeks, Indians, Chinese, Maya, and many ancient indigenous peoples of the Americas."
"Professional astronomy is split into observational and theoretical branches."
"Observational astronomy is focused on acquiring data from observations of astronomical objects."
"This data is then analyzed using basic principles of physics."
"Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena."
"These two fields complement each other. Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results."
"Astronomy is one of the few sciences in which amateurs play an active role."
...such as finding new comets.
"It uses mathematics, physics, and chemistry in order to explain their origin and evolution."
"Amateur astronomers have helped with many important discoveries, such as finding new comets."
"More generally, astronomy studies everything that originates beyond Earth's atmosphere."
"Cosmology is a branch of astronomy that studies the universe as a whole."
"These include the Egyptians, Babylonians, Greeks, Indians, Chinese, Maya, and many ancient indigenous peoples of the Americas."
"Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets."
"Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation."