What does it mean? There are many definitions but the most compact one I have found in the Oulu Space Physics Textbook says: “Space physics is interested in the natural plasma environments found close enough to the Earth to be studied by in situ measurements.” Today, these in situ measurements onboard spacecraft cover most of the heliosphere. However, majority of the spacecraft orbits around Earth. Space Physics studies plasma that has significantly different properties at Sun, in the solar wind, or in planetary environments including Earth.
Last update: 2007-01-21