Star explosion hurls radioactive metal on earth
Our planet, as you know, is constantly bombarded by particles and small space objects originating from various parts of the cosmos. The astronomers did not know that the Earth is being reached - at this moment - for radioactive fragments thrown during stellar explosions (Supernova) that occurred millions of years ago.
According to Bec Crew, from Science Alert website, the discovery took place in two stages: in early April, Australian scientists have noted the presence of a rare type of radioactive metal called iron-60 on the ocean floor in various parts of the world.
Since this material has a half-life of 2.6 million years and is only produced during large spatial explosions, astronomers estimate when and how he got to Earth. As calculated, iron-60 was thrown after the explosion of two stars - one there 6.5000000 to 8.7000000 years, and another for 3.2000000 to 1.7000000 years, respectively. Now comes the second stage of discovery.
According Bec after Australian astronomers announced the discovery, new data from observations conducted by space satellite ACE - Advanced Composition Explorer - NASA, pointed out that, to all appearances, the first star exploded relatively near to Earth, releasing fragments everywhere, including in our direction.
Then the second explosion took place, accelerating the fragments to near the speed of light - and since then, the radioactive material is still "raining" here on our planet. The researchers came to this conclusion after realizing that the ACE is detecting the presence of iron-60 in space for no less than 17 years, which means that new fragments are still coming to our neighborhood today.
Moreover, at first, Australian astronomers deduced that the iron-60 that they had probably found was the time when the explosions occurred. However, the information obtained from the ACE support the theory that the radioactive material may have fallen here for millions of years, but much more recently. But where, after all, there were those explosions?
It's Raining radiation!
The researchers suspect that supernova occurred in a star cluster known as Star Association of Scorpius-Centaurus, which is about 400 light-years away from us. However, while the radioactive material generated during the explosions continue reaching our planet, astronomers said that the Earthlings not need to worry too much about it.
According to them, the spatial satellite ACE is detecting about a single core of iron-60 per year, which means that we do not run the risk of being hit by a huge radioactive fragment star. On the other hand, also need not despise the material just because it's tiny!
Iron-60 would only be a problem if the constant bombardment began to affect the climate of our planet. Anyway, it's amazing the amount of things that astronomers can discover only by analyzing these tiny cores.