COSTEP : Comprehensive Suprathermal and Energetic
Particle Analyser
Not all the particles that come SOHO intercepts come from the Sun. Some appear to come from outside our solar system of even outside our galaxy! This instrument tells us what these particles are and how fast they are.
COSTEP also allows us to follow explosions of energy in the solar atmosphere out towards SOHO.
Pictures courtesy of the SOHO COSTEP consortium.