Promethium has no known biological role. Promethium's longest-lived isotope has a half-life of only 18 years. For this reason it is not found naturally on Earth. It has been found that a star in the Andromeda galaxy is manufacturing promethium, but it is not known how.

Where is promethium naturally found?

Promethium is not found in the Earth's crust. However, it can be observed in uranium ores as a product of uranium decay. In addition, it can be found in the Andromeda galaxy.

How do you get promethium?

Promethium is recovered from the leftovers of uranium fission. It can be produced by bombarding neodymium-146 with neutrons to become neodymium-147, which beta decays over its 11-day half-life into promethium-147, according to the Jefferson Laboratory. The primary use for promethium is for research.