This illustration shows 'quasi-parallel' (top) and 'quasi-perpendicular' (bottom) magnetic field conditions at a planetary bow shock.

Photojournal: PIA16825

February 19, 2013

This illustration shows ''quasi-parallel'' (top) and ''quasi-perpendicular'' (bottom) magnetic field conditions at a planetary bow shock. Bow shocks are shockwaves created when the solar wind blows on a planet's magnetic field.

Under quasi-parallel conditions, the planet's magnetic field is roughly pointing toward the shock surface, almost parallel to a vector at right angles to the shock front (red arrow). Under quasi-perpendicular conditions, the magnetic field is close to aligned with the shock surface, that is, almost perpendicular to the shock vector.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology, Pasadena.

Credit: ESA

ENLARGE