Radiation na Cosmic Microwave Background Radiation (CMBR) yana nufin haske mai haske na microwave radiation wanda ya cika sararin samaniya. Shi ne bayan babban bang, kuma ana tunanin shi ne haske mafi dadewa a sararin samaniya, wanda ya samo asali tun shekaru 380,000 kacal bayan babban bang. CMBR yana nan a kowace hanya a sararin samaniya kuma yana da yanayin zafi kusan 2.7 Kelvin (ko -270.45 digiri Celsius). An yi imanin cewa CMBR yana ba da bayanai masu mahimmanci game da tsari da juyin halitta, kuma masana ilmin taurari da masana sararin samaniya sun yi nazari sosai don fahimtar tushen sararin samaniya da tarihin duniya.