[timothevs]

Quite interesting, do you have an article, or a paper about the prehistoric episode you mentioned? I’m genuinely curious.

[intotheabyss]

The only naturally occurring nuclear fission reactor was found to be in Oklo, Gabon in Central Africa and was thought to be active about 1.5 billion years ago.

https://en.wikipedia.org/wiki/Natural_nuclear_fission_reacto...

[kenned3]

This provides much better coverage: https://blogs.scientificamerican.com/guest-blog/natures-nucl...