While the fundamental ideas involved in this "meteoritic hypothesis" are not seriously controverted, the detailed application of its principles is open to more question, and for the most part those astronomers who hold that in the present state of knowledge stellar spectra furnish a key to a star's age or degree of advancement do not venture beyond broad general statements.
"A Text-Book of Astronomy"
George C. Comstock
Here, at last, was the proof of the meteoritic composition of Saturn's ring.
"The Story of the Heavens"
Robert Stawell Ball
Hence has arisen what is termed the meteoritic theory, which has been ably advocated for many years by Sir Norman Lockyer, and with some unimportant modifications is now becoming widely accepted.
"Is Mars Habitable?"
Alfred Russel Wallace