Definitions for "Solar nebula"
Keywords:  nebular, dust, cloud, billion, ago
cloud of gas and dust out of which a star condenses. The primordial gas and dust cloud from which the sun and planets condensed.
A cloud of gas and dust, rotating around the Sun, nearly in its rotational plane, during the time that the Sun and planets were forming. The planets built up through collisions of bits of dust and ice which were in this cloud, and in the process, acquired orbital motions which are very nearly in the same plane as the original rotation. Also see nebular theory, or planetesimal accretion theory.
fragmented portion of an interstellar cloud that has begun to contract under its own gravitation, eventually leading to the formation of a planetary system.