Where does gold come from? While it can be found on Earth, it originally came from much further away. Now, scientists are taking a closer look at the origins of gold in the universe.

Researchers have long wondered where heavy elements, such as gold, came from. And while several theories have been put forward, researchers haven't been able to pin down which one may be the correct one.

"At this time, no one knows the answer," said Witold Nazarewicz, co-author of the new study. "But this work will help guide future experiments and theoretical developments."

In this latest study, the researchers looked at two possible sources for gold. One is a supernova, which is a massive star that collapsed and then exploded under its own weight. This particular reaction may have caused gold particles to form and explode outward into space. The other option is a neutron-star merger, in which two small and yet incredibly massive stars come together and then eject a massive amount of stellar debris. This debris, in theory, could also include gold particles.

In order to find out which one may be a more viable theory, the researchers used existing data to simulate the production of heavy elements in both supernovae and neutron-star mergers. This, in particular, shows that both may actually be the source of heavy elements.

"Our work shows regions of elements where the models provide a good prediction," Nazarewicz said. "What we can do is identify the critical areas where future experiments, which will be conducted at FRIB, will work to reduce uncertainties of nuclear models."

The findings reveal a bit more about what may have been the origins of heavy particles in the universe. While there are still questions as to the sources, this study shows that at least two theories are viable. This means that in the future, researchers can further study these two theories in order to see what kind of heavy metals are produced and whether one produces more than the other. This, in turn, may reveal a bit more about our early universe.

The findings are published in the March 20116 journal Physical Review Letters.