ESA Science & Technology11-Jul-2005 14:24:29

Plasma Regions

Solar Wind & Bow Shock

Artist's impression showing the main regions/boundaries of the Earth's magnetosphere.

The bow shock is the region where the solar wind is decelerated from supersonic to subsonic speed before being deflected around the Earth. The length scales of various processes occurring at the bow shock are as yet unknown. Cluster  II multi-point measurements should provide some answers.

Further upstream of the bow shock, we need to learn more about electromagnetic waves in the solar wind, in particular about their transmission through the bow shock and the magnetosheath. Cluster  II, which carries five instruments to measure the characteristics of electromagnetic instruments in various frequency domains - STAFF, EFW, WHISPER, WBD and DWP - would be ideally located for this study with, for instance, two spacecraft downstream and two upstream of the bow shock.

For further information please contact: