Dust from a supernova, or an exploded star, has been found in snow in Antarctica, according to a new study.
The discovery, published in Physical Review Letters last week, could shed “invaluable” light on the history of our solar system and its place in the cosmos.
A supernova can occur when an expanding massive star explodes leaving in its wake dust, gas and clouds filled with radioisotopes – or atoms with excess nuclear energy.
Researchers said that, within the last 20 million years, the Earth passed through a stardust cloud -- from one or more stars – and some of it remained in our blue planet’s atmosphere.
And some of the dust ended up on the largely uninhabited continent of Antarctica.
Study co-author and nuclear astrophysicist Dominik Koll, of the Technical University of Munich, told CNN that he’s “happy to actually see something which traveled billions of billions of kilometres through space and is millions of years old.”
The study’s abstract explained that researchers made the discovery after shipping 500 kilograms of snow -- which was less than 20 years old -- from a remote part of Antarctica and then analyzing it at a facility in Munich.
They let the snow melt and tested it with equipment sensitive enough to sift out different particles and anomalies, according to the American Physical Society's brief explainer of the study.
The samples tested positive for a rare particle called Iron-60.
Most of the iron in our universe is Iron-56 but cosmic explosions or nuclear bombs can make the atoms gain more neutrons, turning it into the rarer, heavier isotope Iron-60.
And Koll and his colleagues determined that the Iron-60 came from “interstellar dust” after ruling out that the radioisotopes had come from Earth from things such as fallout from nuclear weapons.
But it’s unclear if the Earth is currently passing through the dust from exploded stars in our “solar neighbourhood” or if the Earth passed through the cloud some years ago.
To figure that out, he and his team plan on testing old ice cores to determine when the supernova occurred and when Earth passed through the interstellar cloud of dust.