KnowraCosmic rayLinked fromLinked fromThe 44 pages that link to Cosmic ray, each with the reason it gives.All 44Broader topic 2Related 30Narrower topic 9Compared with 3Interstellar mediumBroader topic: They ionize interstellar gas and transfer energy through regions that starlight cannot penetrate.Ionizing radiationBroader topic: Cosmic rays are a natural source of energetic, ionizing particles.