Техt 1 star material discovered in South pacific

Interstellar matter formed in a supernova has been discovered on Earth now for the first time. Light coming to Earth from distant supernovas is recorded all the time. Likewise, dozen or so neutrinos from nearby Supernova 1987A have been detected. But atoms from supernovas are a different matter. In a sense, all the heavy atoms on Earth have been processed through or created in supernovas long ago and far away. But now comes evidence of atoms from a supernova that may have been deposited here only a few million years ago. An interdisciplinary team of Germanscientists from the Technical University of Munich, the Max-Planck Institute (Garching), and the
University of Kiel have identified radioactive iron-60 atoms in an ocean sediment layer from a seafloor site in the South Pacific.
First, several sediment layers were dated, and only then were samples scrutinized with accelerator mass spectroscopy, needed to spot the faintly present iron. The half-life of Fe-60 (only 1.5 million years), the levels detected in the sample, and the lack of terrestrial sources point to a relatively nearby and recent supernova as the origin. How recent? Several million years. How close? An estimated 90-180 light years. If the supernova had been any closer than this, it might have had an impact on Earth's climate. The researchers believe traces of the Fe-60 layer (like the iridium layer
that signaled the coming of a dinosaur-killing meteor 65 million years ago) should be found worldwide but have not yet been able to search for it.

Дата добавления: 2015-07-25