Stardust in the Antarctic Snow

Iron-60 discovery in the Antarctic provides information on the environment of the solar system

Kohnen Station in the Antarctic The Kohnen Station is a container settlement in the Antarctic, from whose vicinity the snow samples in which iron-60 was found originate.Credit: Martin Leonhardt / Alfred-Wegener-Institut (AWI)


Antarctic snow travels around the world


Korschinek and Dominik Koll from the research area Nuclear, Particle and Astrophysics at TUM found five iron-60 atoms in the samples using the accelerator laboratory in Garching near Munich. "Our analyses allowed us to rule out cosmic radiation, nuclear weapons tests, or reactor accidents as sources of the iron-60," states Koll. "As there are no natural sources for this radioactive isotope on Earth, we knew that the iron-60 must have come from a supernova."

Stardust comes from the interstellar neighborhood


"Our solar system entered one of these clouds approximately 40,000 years ago," says Korschinek, "and will exit it in a few thousand years. If the gas cloud hypothesis is correct, then material from ice cores older than 40,000 years would not contain interstellar iron-60," adds Koll. "This would enable us to verify the transition of the solar system into the gas cloud—that would be a groundbreaking discovery for researchers working on the environment of the solar system.