Andrew F. Nagy Originally published in the journal Space Science Reviews, Volume 139, Nos 1-4. DOI: 10. 1007/s11214-008-9353-0 (c) Springer Science+Business Media B. V. 2008 Keywords Aeronomy The term "aeronomy" has been used widely for many decades, but its origin has mostly been lost over the years. It was introduced by Sydney Chapman in a Letter to the Editor, entitled "Some Thoughts on Nomenclature", in Nature in 1946 (Chapman 1946). In that letter...