Wind first will take readings in the turbulent area where particles of the solar wind are reflected from a shock wave that forms when this wind encounters the Earth's magnetic field. This supersonic shock wave, known as the bow shock, occurs in front of the magnetosphere where the outward force of the compressed geomagnetic field is balanced by the force of the solar wind. Later, Wind will be repositioned in to a circular orbit between the Sun and the Earth to observe the solar wind before it intercepts the magnetosphere. The Radio and Plasma Waves instrument will measure the properties of these waves and other wave modes of the plasma over a very wide frequency range. Space Flight Center - SWE will measure ions and electrons in the solar wind and the foreshock regions at a rate of once per minute for ions and 20 times per minute for electrons.
Measurements made in the foreshock are important for understanding the structure of the bow shock.
From these measurements, the solar-wind velocity, density, temperature and heat flux can be deduced. Electron and ion velocity distributions should reveal properties of the flowing plasmas and their pivotal role in the transfer of mass, momentum and energy from the Sun to the Earth. Because the solar wind is an extension of the corona, from which it is accelerated, these measurements also assist in studies of the Sun. The magnetic field measurements from MFI are especially important to the interpretation of other data from Wind. This direct sampling of solar matter is a way to study events on the solar surface and the incorporation of solar material into the solar wind.