Complex sentence: Clayton predicted a new astronomical discipline based on the relative abundances of the isotopes of chemical elements as they would condense in hot gases leaving stars into solids called "stardust", a component of Cosmic dust found later to be distributed within meteories.
Split into simpler sentences: Clayton predicted a new astronomical discipline based on the relative abundances of the isotopes of chemical elements as they would have condensed into solids from the hot gases leaving stars. Clayton named these solids "stardust", a component of Cosmic dust found later to be distributed within meteories.