Traces of freshly made plutonium and radioactive iron recovered from the bottom of the Pacific Ocean are contributing to an understanding of how heavier elements are created from exploding stars and other cosmic events, according to a National Public Radio report.
Citing a report in the journal Science, NPR said that the material was deposited on Earth from outer space within the last 10 million years.
The culprits: While hydrogen and helium were born in the Big Bang, and slightly heavier elements such as carbon and oxygen form in the cores of stars, astronomers believe the heaviest elements on the periodic table require more intense cosmic events, such as the explosion of massive stars as supernovae.
By looking at trace amounts of Pu-244, which does not exist naturally on Earth, with quantities of Fe-60, which is known to be the product of supernovae, researchers were able to evaluate models used to predict how the elements are formed through the rapid neutron capture process.
The study suggests that supernovae are not the sole source of the heavier elements, adding to a growing body of evidence that colliding neutron stars are responsible for the formation of these materials.