galaxy a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.

abstract alien andromedas astrology astronomy attraction aurelius aurora billions blue cluster cosmos creation dust earth education element energy explosion exposure field future galaxy gas globe glow god grain graphic gravitational held jupiter long mars milky millions moons nebula night nova orange orbit outer photograph planet planets pluto saturn science scifi sky solar space star starry stars study sun supernova system together universe venus way world