Ancient supernova particles found in deep-sea sediments on the Earth

The Earth and the solar system are regularly showered by the products of supernovae, which are the most powerful explosions in the known universe. Now, a recent study highlights that there is tangible evidence that point towards such a phenomenon, describing rare isotopes of iron found in deep-sea sediments that are at least 33,000 years old.

Representative image of a supernova.[/caption]As per the statement, the study, which has been led by Professor Anton Wallner, a nuclear physicist at ANU, shows the Earth has been travelling for the last 33,000 years through a cloud of faintly radioactive dust. 

According to Professor Wallner, the clouds seem to be remnants of previous supernova explosions, "a powerful and super bright explosion of a star."

Researchers searched through several deep-sea sediments from two different locations about 33,000 years ago, using the extreme sensitivity of HIAF's mass spectrometer. The researchers found clear traces of the isotope iron-60, which is formed during supernova explosions.

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The researchers said Iron-60 is radioactive and completely decays away within 15 million years. This points towards the fact that any iron-60 found on the earth must have been formed much later than the rest of the 4.6-billion-year old earth and arrived here from nearby supernovae before settling on the ocean floor.

Subsequently, the team found iron-60 in the sediment at extremely low levels - equating to radioactivity levels in space far below the Earth’s natural background levels. The distribution matched the Earth’s recent travel through the interstellar cloud. However, researchers found the iron-60 extended further back and was spread throughout the entire 33,000 year measurement period.

According to Professor Wallner, the iron-60 could originate from even older supernovae explosions, and what they measured is some kind of echo.

The findings were reported in the Proceedings of the National Academy of Sciences.