Interstellar isotopes! > By studying geological radioisotopes on Earth, we can learn about the past of the heliosphere. Fe60 is predominantly produced in super

Interstellar isotopes! > By studying geological radioisotopes on Earth, we can learn about the past of the heliosphere. Fe60 is predominantly produced in supernova explosions and becomes trapped in interstellar dust grains. Fe60 has a half-life of 2.6 Myr, and Pu244 has a half-life of 80.7 Myr. Fe60 is not naturally produced on Earth, and so its presence is an indicator of supernova explosions within the last few (~10) million years.