Space plasma physics, pushed by the impressive recent technological developments, is undergoing a period of intense progress. This progress is achieved first at the level of observations, including both remote and in situ measurements, but also on the theoretical side, mainly by means of large scale numerical simulations made possible by the dramatic increase of computational resources. In particular, three-dimensional mainly hybrid but also fully kinetic simulations are today feasible, and

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... e intervals in spatial and time scales can at last be accessed by fluid simulations. Addressing fundamental problems such as, e.g. magnetic reconnection, nonlinear dynamics or turbulence development in the kinetic range, are no longer just a heart's desire today. It is common to assert that the Solar Wind is a laboratory for plasma physics in particular because of the possibility of very accurate measurements of the main fields, but also of the distribution functions. A great success of space plasma physics has been the possibility of exhibiting the collisionless character of plasmas by measuring non-Maxwellian distribution functions more or less everywhere in space. Even further, the terrestrial environment is truly an exclusive laboratory in what concerns the study of turbulence of Alfvénic type, a phenomenon for which experiments are in their infancy due to lack of scale separation. All basic questions about usual fluid turbulence have to be reformulated in the context of Solar Wind turbulence. The physical mechanisms at the origin of dissipation, the typical scales involved, and the link with coherent structures and/or wave particle resonances are among the most difficult problems. Basic issues such as the role or even existence of waves are still debated. Furthermore, in addition to waves, this medium is also affected by macro/micro-instabilities whose nonlinear evolution is still the subject of intensive theoretical investigation because of their role in redistributing in the system the energy injected typically at very large scales. In this sense, micro-instabilities often play a role similar to what one would expect from collisions at much smaller scales. Great advances in the description of the Alfvénic cascade, its dissipation range and more importantly its 3D spatial structure, were recently made using the four Cluster satellites. Substorms and aurora dynamics were the object of detailed investigation with the five satellite mission THEMIS, while the four satellite mission MMS, to be launched in a near future, should allow for a closer look at reconnection in the † Email address for correspondence: passot@oca.eu https://www.cambridge.org/core/terms. https://doi.