Cosmic rays
Image shows 83.33 hours of cosmic ray particles striking a Hamamatsu ORCA-ER digital CCD camera. Each of the three color channels are 10,000 exposures, 10 seconds each. Camera background has been removed and gamma adjusted for better contrast. August 7, 2012, marks the 100th anniversary of the discovery of cosmic rays.
— George McNamara, Analytical Imaging Core Facility, University of Miami.