CHICOS - California HIgh school Cosmic ray ObServatory :
- An active research array for the detection of ultra-high energy cosmic rays. The events CHICOS is designed to observe are single subatomic particles slamming into the Earth's atmosphere with the energy of a brick falling from a rooftop. It is a collaboration of Los Angeles-area high schools, California Institute of Technology, California State University, Northridge, and University of California, Irvine.