Galileo-Ulysses-Cassini-Stardust 2001 Workshop Heidelberg July 18-21, 2001 Io Revealed in the Jovian Dust Streams Amara Graps, Eberhard Gr\"un, Harald Kr\"uger Max-Planck-Institut f\"ur Kernphysik, Heidelberg, Germany Mih\'{a}{\l}y Hor\'anyi LASP, Boulder, USA H{\aa}kan Svedhem, ESTEC, Noordwijk, Netherlands and the Galileo and Cassini Dust Science Teams PROBLEM TO SOLVE Indirect methods applied by previous researchers have pointed to Io being the simplest explanation for the question of the origin of the Jovian dust streams. Problem: {\it Can I show by direct methods that Io is, or Io is not, the source of the Jovian dust streams?} If the answer to that question is `Yes', then: {\it Please explain some of the physical phenomena of the Jovian dust streams, such as the measurements of the December 2000 Galileo-Cassini in-situ measurements.}