Editing Observational cosmology (section)

===Nuclide abundances===
{{main|cosmochemistry|astrochemistry}}
Determination of the [[Abundance of the chemical elements#Abundance of elements in the Universe|cosmic abundance of elements]] has a history dating back to early [[spectroscopy|spectroscopic]] measurements of light from astronomical objects and the identification of [[emission line|emission]] and [[absorption line]]s which corresponded to particular electronic transitions in [[chemical element]]s identified on Earth. For example, the element [[Helium]] was first identified through its spectroscopic signature in the [[Sun]] before it was isolated as a gas on Earth.<ref>''The Encyclopedia of the Chemical Elements'', page 256</ref><ref>''Oxford English Dictionary'' (1989), s.v. "helium". Retrieved December 16, 2006, from Oxford English Dictionary Online. Also, from quotation there: Thomson, W. (1872). ''Rep. Brit. Assoc.'' xcix: "Frankland and Lockyer find the yellow prominences to give a very decided bright line not far from D, but hitherto not identified with any terrestrial flame. It seems to indicate a new substance, which they propose to call Helium."</ref>

Computing relative abundances was achieved through corresponding spectroscopic observations to measurements of the elemental composition of [[meteorite]]s.
<!--A compilation of results is found [[Cosmochemical Periodic Table of the Elements in the Solar System|here]].-->