The geomagnetic field extending outward beyond Earth’s solid surface encounters a strong, highly variable flow of hot ionized gas from the Sun called the solar wind. This compresses and shapes the dayside of Earth’s magnetic field. On the night (anti-sunward) side of the Earth, the magnetic field gets drawn out into a long, comet-like tail. Present evidence is that this magnetotail region extends to hundreds or thousands of Earth radii. Research over the past six decades has revealed much about the various current systems that shape the Earth’s "magnetosphere". This chapter is devoted to providing a broad overview of the individual current systems that, acting together, generate the complex and fascinating geomagnetic field.

Scientific results about space physics in the solar system and obtained from space missions are presented, concentrating on observations from the past decade. After giving the most exhaustive possible list of missions having journeyed in the solar system these past twenty years, the paper presents new insights gathered on the solar wind focusing in particular on results obtained with SOHO, STEREO, ACE and Wind. Then, new results are also presented regarding the terrestrial space environment focusing specifically on data gathered by Cluster, Polar, THEMIS, GEOTAIL and Double Star.