 The elemental abundances of some C-chondrite groups (with the obvious exception of hydrogen, helium, and some other elements, see below) have long been known to resemble solar abundance values.The CI chondrites, in particular, correspond "quite closely, more so than does any other type of meteoric or terrestrial matter"; called "somewhat miraculous".Of course, only gas giant planets have the mass to retain, explicitly, hydrogen and helium.