\u201cThe story doesn\u2019t fit perfectly, though,\u201d Koll wrote in a column for The Conversation<\/a>. The ice samples studied had less iron-60 than anticipated, but they\u2019re nevertheless imprints of the cosmic cloud in Earth\u2019s geological record, he added.<\/p>\n Static, but vibrant <\/p>\n According to Koll, it\u2019s not incredibly uncommon for tiny grains of supernova dust to trickle down to Earth\u2019s surface. But that surface teems with activity and drastic changes, which is why Antarctica serves as a valuable location for studying geological records. The snow and ice in Antarctica form a \u201clargely undisturbed\u201d and layered record spanning tens of thousands of years, he added.<\/p>\n When researchers first discovered iron-60 in Antarctic surface snow that was less than 20 years old, they were actually divided as to how this isotope ended up there. Koll\u2019s team suspected that the Local Interstellar Cloud could store iron-60 for a long time and gradually deposit the isotope on Earth. But they didn\u2019t have enough proof at the time, Koll explained in a statement<\/a>.<\/p>\n Well worth the pain <\/p>\n The latest findings describe how the team gathered enough evidence for their \u201ceducated guess,\u201d as Koll described it in his column. The \u201cpainstaking\u201d process involved melting and chemically treating the ice to isolate tiny amounts of iron, then using a particle accelerator to count a handful of iron-60 atoms out of 10 trillion particles.<\/p>\n Surprisingly, this analysis found significantly lower levels of iron-60 than expected, compared to more recent Antarctic samples. That indicated that less iron-60 reached Earth between 40,000 and 80,000 years ago, which was the age of the ice samples in the study. The results were also somewhat inconsistent with the idea that these iron-60 deposits were fading traces of ancient supernovas from millions of years ago.<\/p>\n Closer to home <\/p>\n![\"Ice](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/05\/ice-core-segment-antarctica-1280x986.jpg\")
An ice core segment extracted from Antarctica. Credit: NASA Goddard Space Flight Center and Ludovic Brucker via Wikimedia Commons <\/p>\n