When meteorites formed, 4.5 Gyr ago, they contained radioactive such as ²⁶Al (T_1/2 = 0.64 Myr) and ⁶⁰Fe (T_1/2 = 2.6 Myr). The origin of these elements and their astrophysical relevance has long been elusive. I will try to show that they are the tracers, at the meteorite scale, of sequential star formation as observed today at the Galactic scale.