A team of scientists suggests a solution to the Galactic radioactive plutonium puzzle. All the Plutonium used on Earth is artificially produced in nuclear reactors. Still, it turns out that it is also produced in nature. Plutonium is a radioactive element. Its longest-lived isotope is plutonium-244 with a lifetime of 120 million years.
from Geochemistry News -- ScienceDaily http://ift.tt/1RCn7w4