New snow research scientists in Antarctica have discovered a rare iron isotope in interstellar dust hidden inside it. This discovery may provide important information about the history of stellar explosions in our galaxy region.
We know that cosmic dust tends to drift down to Earth all the time, small debris from the formation of stars and planets, sometimes billions of years old. Antarctica is a great place to search for such dust particles, because this is one of the most unspoiled areas on Earth, making it easy to find non-native isotopes from our planet. than.
In this case, the isotope that researchers have identified is exactly the 60-isotope of iron, one of many radioactive variations of iron. Previously, the presence of this type of iron in deep-sea sediments and fossilized remains of bacteria suggested one or more supernovae exploding in the vicinity of the Earth between 3.2 and 1.7. million years ago.
The new study marks the first time an interstellar iron-radioisotope 60 has been detected in Antarctic snow, which is believed to have fallen from the sky over the past 20 years.
"I was surprised, personally, because it was just a theory that there could be 60 iron isotopes and not even sure that the signal was strong enough to be detected. It was a very happy moment. when I see the number of 60 iron isotopes appearing in the data, because that means our overall astronomical picture may not be too wrong, " said Dominik Koll, a nuclear physicist from the University. Australian country said.
The solar system is currently passing through the region called the local interstellar cloud (LIC) - a dense interstellar bag containing several interstellar dust clouds.
If the 60 iron isotope has been deposited on Earth in recent years, that helps validate the idea that our galaxy region and the special structure of interstellar stars can has been shaped from exploding stars.
Basically there is no stable iron or other elements that are abundant in Antarctica, which is very helpful for measuring the rate of iron isotope 60. Snow is obtained by contacting and packed in boxes. Storage is kept below 0 degrees Celsius to keep snow frozen until Munich.
The researchers measured the ratio of other elemental isotopes in their samples, to ensure that the 60-iron isotope is actually of interstellar origin. This allows the elimination of a potentially different source, such as space rocks in our Solar System that are irradiated with cosmic rays, or even nuclear weapons testing.