Looking at programmes of geo- and cosmochemistry meetings, I am always impressed by how much science can be illuminated by a single group of elements – the noble gases. I have covered a very small part of this in these pages, but especially at dedicated noble gas meetings like the DINGUE series, I am always amazed at what colleagues are working on that I had no idea about. This fascinating aspect is not unique to noble gases, but at least from my point of view, noble gas geo- and cosmochemistry represents a particularly striking example. Alex Halliday notes in his preface to the book about noble gas geo- and cosmochemistry I co-edited with my colleagues Don Porcelli and Chris Ballentine (Porcelli et al., 2002) that “discoveries that have been made with noble gas geochemistry are of such a profound and fundamental nature that earth science textbooks should be full of examples …. [and] noble gas geochemistry is a broader and more versatile field than almost any other area of geochemistry”. However, Alex also points out that noble gases are not as popular in textbooks and earth science teaching as they deserve to be. This is a problem reflecting the complexities that come along with the particular advantages of noble gases. Their rarity in most environments leads to detectability of a multitude of “components” produced by specific processes that would go unnoticed for most other elements. Minoru Ozima and Frank Podosek noted in the first edition of their classic book on noble gas geochemistry that “noble gas geochemistry often seems to non-practitioners to have much the air of the secret society and its dark art”. I would add that even practitioners can quite easily get lost in the component jungle of the “noble gas alphabet”. In the preceeding pages, I hope to have dispelled some of the darkness from the art of our beautiful area of science.

I also hope that this article reflects how much I enjoyed and continue to enjoy being part of a community whose activities range from studying the Sun, the early solar system and its later history, cosmic rays, meteorite delivery, and interstellar processes, to the history of and processes in the Earth, from its interior to its surface.

) Noble Gases in Geochemistry and Cosmochemistry.
Reviews in Mineralogy and Geochemistry
Mineralogical Society America, Geochemical Society
Washington DC.