ИСТИНА

Electric currents are fundamental to the structure and dynamics of space plasmas, including our own near-Earth space environment (also called “geospace”). This recognition is one of the great achievements in space research, going back to the beginning of the last century. With the current multi-spacecraft missions, such as Cluster, THEMIS and Swarm, we have unprecedented opportunities to unravel many of the intriguing puzzles about electric currents, such as: How are electric currents generated, maintained, and dissipated? What is their three-dimensional spatial structure (topology)? What is the relationship among various scales? What is their temporal development, both short and long term? How do the currents affect their space environment? How much energy is transported and deposited in various regions by currents? In addition to advances in our own geospace, much knowledge has been accumulated about planetary and solar current systems. Recent space missions that have provided data in the last decade or so to study current systems in planetary magnetospheres include: Cassini, MESSENGER, and Venus Express and now Maven. Juno will provide data on high latitude current systems at Jupiter when it arrives in July 2016. Two recent space missions, the Hinode satellite and the Solar Dynamics Observatory spacecraft, have provided new information on electrical currents at the level of the Sun’s photosphere, as well as high resolution X-ray and extreme-UV and X-ray images of solar activity powered by coronal currents.