A cewar ƙamus, cosmic ray yana nufin wani ƙwayar atom ɗin mai kuzari mai ƙarfi ko kuma wani barbashi wanda ya samo asali daga sararin samaniya kuma yana tafiya ta sararin samaniya, wani lokaci kuma yana yin karo da yanayin duniya kuma yana haifar da radiation na biyu wanda ake iya ganowa a saman. Hasken sararin samaniya na iya haɗawa da protons, electrons, da atomic nuclei na abubuwa daban-daban, kuma ana tunanin cewa supernovae, black holes, da sauran abubuwan tashin hankali na taurari ne suka samar da su.