(physics) the force of attraction between all masses in the universe.
the early, incorrect model of our solar system with the earth in the center.
the accepted model of our solar system with the sun in the center.
everything that exists anywhere.
(astronomy) a collection of star systems.
Milky Way Galaxy
the name of our galaxy, a spiral galaxy that contains about 400 billion stars.
any celestial body visible (as a point of light) from the Earth at night.
any of the celestial bodies (other than comets or satellites) that revolve around the sun in the solar system.
the sun with the celestial bodies that revolve around it in its gravitational field.
the distance light travels in one year.
a unit of length used for distances within the solar system.