1. On today’s Fresh Air, how supernovas — like the one pictured above — helped scientists measure how fast the universe is expanding. 


Tycho’s Supernova Remnant: Tycho’s Remnant Provides Shocking Evidence for Cosmic Rays (The hot, expanding debris of a supernova observed in 1572.) (by Smithsonian Institution)

    On today’s Fresh Air, how supernovas — like the one pictured above — helped scientists measure how fast the universe is expanding

    Tycho’s Supernova Remnant: Tycho’s Remnant Provides Shocking Evidence for Cosmic Rays (The hot, expanding debris of a supernova observed in 1572.) (by Smithsonian Institution)