"nebular hypothesis." YourDictionary, n.d. Web. 12 October 2018. <http://www.yourdictionary.com/nebular-hypothesis>.
nebular hypothesis. (n.d.). Retrieved October 12th, 2018, from http://www.yourdictionary.com/nebular-hypothesis
A hypothesis concerning the formation of stars and planets, and therefore the origin of the solar system, according to which a rotating nebula underwent gravitational collapse into a star with an accretion disk, from which planets condensed or formed by coagulation of dust particles into increasingly larger bodies.