الدراسات من النيازك تشير إلى أن النظائر المشعة مثل الألومنيوم-26 مع فترة نصف العمر من 7.17 × 105 سنوات، و البوتاسيوم 40 مع عمر نصف من 1.250 × 10 <سوب>9 years, isotopes mainly produced in supernovae, were much more common.
Studies of meteorites suggests that radioactive isotopes such as aluminium-26 with a half-life of 7.17×105 years, and potassium-40 with a half-life of 1.250×109 years, isotopes mainly produced in supernovae, were much more common.