The study of the region of space near the Earth helps to determine changes in the Earth's magnetosphere, ionosphere, and upper atmosphere in order to enable specification, prediction, and mitigation of their effects. Heliophysics seeks to develop an understanding of the response of the near-Earth plasma regions to space weather. This complex, highly coupled system protects Earth from the worst solar disturbances while redistributing energy and mass throughout.
A key element involves distinguishing between the responses to external and internal drivers, as well as the impact of ordinary reconfigurations of environmental conditions, such as might be encountered when Earth crosses a magnetic sector boundary in the solar wind. This near-Earth region harbors spacecraft for communication, navigation, and remote sensing needs; conditions there can adversely affect their operation. Ground based systems, such as the power distribution grid, can also be affected by ionospheric and upper atmospheric changes. Key near-term investigations emphasize understanding the nature of the electrodynamic coupling, how geospace responds to external and internal drivers, and how the coupled middle and upper atmosphere respond to external forcings and how they interact with each other.
A magnetosphere is that area of space, around a planet, that is controlled by the planet's magnetic field. The shape of the Earth's magnetosphere is the direct result of being blasted by solar wind. It prevents most of the particles from the Sun, carried in the solar wind, from hitting the Earth. The Sun and other planets have magnetospheres, but the Earth has the strongest one of all the rocky planets. The Earth's magnetosphere is a highly dynamic structure that responds dramatically to solar variations. Life on Earth developed and is sustained under the protection of this variable magnetosphere.