Supernova Shrapnel Found In Meteorite 105
coondoggie writes "Talk about finding a needle in a cosmic haystack. Scientists this week said they found microscopic shrapnel in a meteorite of a star they say exploded around the birth of our solar system 4.5 billion years ago."
Supernova Shrapnel??? (Score:3, Informative)
Re:Supernova Shrapnel??? (Score:5, Informative)
isn't any atom heavier than Fe technically supernova shrapnel?
Not if you consider "shrapnel" to mean "fragments that are small but not gaseous". The point here is that a nanoscale grain of chromium54 has been found, which suggests it cooled out of the supernova gas cloud and was driven into the meteroite during a collision, so it is a more-or-less pristine piece of supernova condensate that has not been processed further, the way the iron on Earth has, for example.
That's a fairly interesting find, I'd say.
Re:Supernova Shrapnel??? (Score:3, Informative)
Re:Shrapnel of a star in a meteorite? (Score:3, Informative)
The idea is that the supernova exploded, send out a shell of gas (as supernovas do), and that this shell of gas mixed into the nebula forming the solar system, giving us lots of heavy elements, and highly amplified concentrations (but still trace amounts) of various isotopes coming from the decay of very radioactive isotopes only formed in supernova. Since these particular supernova products decay rapidly, in general galactic matter they would be hard to find, so finding their decay products is a clear sign of proximity to a supernova event.
The particles in question here are 100 nanometers across, and presumably condensed as the supernova shell cooled. Calling them "Shrapnel" is misleading - they would make a virus look huge. I would call them smoke particles, but they are even smaller than that.
Re:Lots of supernova remnants around (Score:5, Informative)
Almost right. You can only really make those heavier elements through processes which occur during a supernova, yes. But although lighter elements (say, carbon) can be made during normal stellar lifetimes...how are you going to get it out?
I found a supernova remnant this morning. It was my foot.
The article is a little less than clear about the actual research that occurred, as usual. From the sound of it, I suspect that what they found was discrete ejecta - a blob of material which recognizably came from a specific supernova which had not mixed with other material. This is cool since it gives us a sample which we can study in that specific context.