cosmogony
astronomy
cosmogony, in astronomy, study of the evolutionary behaviour of the universe and the origin of its characteristic features. For scientific theories on the unsolved problem of the origin of the solar system, see planetesimal; protoplanet; solar nebula. For an outline of the development of astronomical ideas regarding the structure of the universe, see cosmology; for theories on the origin of the universe, see big-bang model; steady-state theory.