At the MOP 2011 (Magnetospheres of Outer Planets conference, Boston), a dedicated workshop was held in order to:
(1) list and debate all observational constraints, with their degree of confidence
(2) list all proposed models and explanations,
(3) examine critically each model's pros and cons (merits and drawbacks, strengths and shortcomings) in the light of the observational constraints,
(4) debate compatibilities and incompatibilities between the models and define observations that will allow us to discriminate between them.

It has then been decided to set collaborative community web services to extend this workshop.