Extraterrestrial Plutonium Atoms Turn Up on Ocean Bottom

The rare form of the element found on the Pacific seabed points to its violent birth in colliding stars.

Scientists studying a sample of oceanic crust retrieved from the Pacific seabed nearly a mile down have discovered traces of a rare isotope of plutonium, the deadly element that has been central to the atomic age. They say it was made in colliding stars and later rained down through Earth’s atmosphere as cosmic dust millions of years ago. Their analysis opens a new window on the cosmos. “It’s amazing that a few atoms on Earth can help us learn about where half of all the heavier elements in our universe are synthesized,” said Anton Wallner, the paper’s first author and a nuclear physicist. Dr. Wallner works at the Australian National University as well as the Helmholtz Center in Dresden, Germany.