we thank Johannes for providing us with the occasion to gather in his name and for shaping and supporting the careers of so many of us. May 2007 R. von Steiger, G. Gloeckler, G.M. Mason Space Sci Rev (2007) 130: 3–4 DOI 10.1007/s11214-007-9240-0 Acknowledgement Published online: 21 July 2007 © Springer Science+Business Media B.V. 2007 Early in 2006, Edward C. Stone, Principal Investigator of NASA’s Advanced Composition Explorer (ACE); Len A. Fisk, Chair of the Space Studies Board of the US National Research Council; and the Directorate of the International Space Science Institute (ISSI), Roger M. Bonnet, Andre Balogh and Rudolf von Steiger, agreed to hold a joint ACE/ISSI Symposium on the “Composition of Matter”, at the occasion of my 80th birthday. I feel deeply honoured by this exceptional distinction and was thrilled to participate, because for more than 50 years my research has been centred around measurements of the composition of matter of various origins, reaching—in geocentric coordinates—from deep-sea sediments to the limits of solar in uence, where comets come from and where the solar wind meets the interstellar medium. The symposium at Grindelwald, beautifully located at the foot of the Bernese Alps, was organised by Ruedi von Steiger, Silvia Wenger and Barbara Gerber, who created the special atmosphere for which ISSI meetings have become known.

Introduction by: R. von Steiger, G. Gloeckler, G.M. Mason