Cosmic ray

Cosmic rays are very heich-energy particles, mainly oreeginatin ootside the Solar Seestem.^[1] Thay mey produce showers o seicontary particles that penetrate an impact the Yird's atmosphere an whiles even reach the surface. Componed primarily o heich-energy protons an atomic nuclei, thay are o mysterious origin. Data frae the Fermi space telescope (2013)^[2] hae been interpreted as evidence that a significant fraction o primary cosmic rays originate frae the supernovae o massive starns.^[3] Houiver, this is nae thoucht tae be thair anly soorce. Active galactic nuclei probably an aa produce cosmic rays.