In a recent analysis of Antarctic snow, scientists made a surprising discovery – a good part of this thin white matter is actually stardust.
A team of scientists recently collected 1,000 pounds of snow from Antarctica, melted it, and sifted through the particles. To their surprise, the snow contained large amounts of a type of iron not naturally found on Earth.
Another terrestrial iron, called iron-60, contains four more neutrons than Earth’s kind.
An extremely heavy metal is the type typically produced by massive, old, and dying stars – or a “supernova”.
Inside Science explains that smaller stars emit lighter “minerals” like carbon and oxygen. The older a star is, the more minerals are produced:
“Iron is usually the last element a star can produce while it is still generating energy, and after the final stages of its life it explodes.”
“It must have been a supernova,” says Dominic Cole, a physicist at the Australian National University, “not so close to killing us, but not so far away that it cannot be diluted in space.”
Koll and his team published their analysis of the material in Physical Review Letters.
The same rare iron isotope was previously found deep in the ocean crust. But given its depth, Iron-60 likely settled millions of years ago. In Antarctica, iron has been found in new layers of snow that have accumulated over the past two decades.
Our planet may have ingested stardust as it traveled through the local interstellar cloud, also known as the “local fluff”.
“This region, which stretches for 30 light years and which our solar system currently traverses and will soon leave,” says Cole, “was likely formed by the explosion of massive stars that release hot gases in their outer layers into space.”