Researchers found dust from the explosion of a star, or supernova, in the snow of Antarctica, according to a study published this month.
The discovery could offer lessons about the history and location of the solar system in its environment, according tot he studies authors.
A supernova occurs when a star explodes and produces clouds or gas and dust enriched with radioisotopes. According to the study, some of the dust from one or more stars fell to Earth sometime in the last 20 million years. It has now been found in the snow of the sparsely inhabited continent.
“I am very pleased and happy to see something that traveled billions of kilometers through space and is millions of years old,” said Dominik Koll, a nuclear astrophysicist who led the discovery and co-authored the study. “Being able to use data on Earth is quite exciting.”
Koll told Tech Life that the researchers made the discovery after sending 500 kg (approximately 1,100 pounds) of snow from Antarctica to a research facility in Munich, Germany.
The researchers selected the remote area precisely because it remains unexplored. They chose to test the snow because “it is the purest material that can be found,” Koll said.
The snow melted and sifted. The materials it contains were incinerated and tested using equipment sensitive enough to detect anomalies.
Samples tested positive for iron-60.
Most of the iron in the universe is iron-56. Iron 60, which has more neutrons that make it unstable to radioactive decay, is present on Earth only by cosmic explosions or nuclear weapons. The researchers were able to determine that the most likely source of iron-60 found in Antarctic snow was stardust, Koll said.
However, it is not clear if the Earth is currently in a cloud of dust or if the discovery is of the remains of a cloud that happened years ago, Koll said.
However, the finding could give clues about the place of the Earth in the universe and information about the structure and origin of the cloud.
“You learn a lot about the dynamics, about the solar neighborhood,” Koll said. “It means that we understand everything about the process and the dynamics, that everything fits together.”
Koll said the next step is to test the deposits of the oldest ice cores to find out when and where the supernova occurred and when our solar system entered the space dust cloud.
The study was published August 12th in Physical Review Letters.
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