Revision of Origin from May 24, 2009 - 10:35am

Cosmic rays is the collective name for energetic particles of different origins:

• High-energy galactic cosmic rays (GCRs) penetrate the solar system - also called the heliosphere - from sources in our Galaxy or still farther away.
• A second population is the anomalous cosmic rays (ACRs), with interstellar neutral atoms as parents.
• A third population has an internal source: the Sun itself (solar cosmic rays, SCRs; also called solar energetic particles, acronym SEPs).