Plutonium 244 Was Found on the Ocean Floor
Similar to iron-60, plutonium-244 is not the kind of isotope that appears out of thin air. There aren't any isotopes of plutonium that, unlike iron, you really want to get too close to. There are a total of 20 of them, and while they are all radioactive, plutonium-244 is the most stable.
In 2021, plutonium-244 traces were discovered in the ocean floor, and it is thought that they traveled a long way to get there. Plutonium-244 is produced under some extremely demanding conditions. In this instance, two stars collided and caused a significant explosion, which produced the plutonium. Along with iron-60, it most likely also develops in supernovae.
Plutonium-244 is not at all an isotope that can be produced easily on Earth. Nuclear reactors produce a variety of isotopes, but plutonium-242 only has a short half-life as 243 and cannot further decay to plutonium-244 due to this. Nuclear weapon explosions have been predicted to create 244, however this is simply a prediction and has not been verified.
