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Supernova May Explain How Planets are Formed
ExE122 writes "A young pulsar that formed from a supernova which happened about 100,000 years ago and is sitting 13,000 light years away may solve some questions about the origins of Earth. From the article: 'Scientists think they have solved the mystery of how planets form around a star born in a violent supernova explosion, saying they have detected for the first time a swirling disk of debris from which planets can rise. The discovery is surprising because the dusty disk orbiting the pulsar, or dead star, resembles the cloud of gas and dust from which Earth emerged. Scientists say the latest finding should shed light on how planetary systems form.'"
Has nothing to do with the earth's age. The article is only talking about the formation of planets around a supernova - and that is not what happend in our solar system.
Not lead, iron. In order to fuse iron to anything higher, you have to add energy, rather than getting energy from it. Once a star starts creating iron in its core, it takes only about 24 hours to burn as much as it's going to. Then, as it contracts, the iron heats up until it suddenly breaks down into helium, taking back all the energy it's given out. That causes a catastrophic collapse, followed by the explosion known as a supernova. Among other things, this generates enough energy to fuse iron into higher elements, so that all elements above iron (including lead) to be the product of a supernova.
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What?
The explosion in the article happened 13,000 light years away. That's a measure of distance. This has nothing, repeat nothing, to do with our solar system. Our solar system was formed as the result of a supernova *more* than 5 Billion years ago. The U238 on our planet is the remnant from *that* supernova, not from one that happened 100,000 years ago.
Sheesh.
On the other hand, if your rather confused grammar is trying to say that the precursor star to the sun (or many precursor stars as supernovas often occur in groups -- being formed from groups of super-giant blue-white stars [see Pleides]) created all the U238 4.6BYA and that the Earth must therefore be less than 4.6BY old. If that's the case, then yeah, maybe the Earth itself is less than 4.6BY old. So what? It just means that the rock it formed from took a little while to condense into its current shape. It's not like the Earth formed, oceans, mountains, and all on Tuesday the 13th of July, 4,600,000,000 BC. It takes tens of millions of years for the matter to acrete into a planet.
If you're wondering in general did all the U238 come from a supernova, then the answer is simple. Yes. So did every element heavier than iron on the periodic table. A supernova is the only place those elements can be formed in nature (at least in any quantity.)
Iron is the energy dead end. When a star runs out of hydrogen, it starts "burning" Helium, when it's out of Helium it starts "burning" boron, and carbon, and oxygen into heavier elements. But when it hits iron, that's the end of the road. There's simply no more energy to get out by fission or fusion. The star is effectively dead. The trick is, if a star can actually reach the silicon "burning" stage where iron is the byproduct, then it's so massive, it's going to go supernova anyway. Part of the energy of the supernova goes into fusing Iron and other leftover bits to produce elements higher on the periodic table. This *costs* energy, so the only place it can happen is a supernova. Thus every element higher than iron (Silver, gold, platinum, lead, mercury, uranium, praseodimium, lanthanum, radium, etc.) had to be formed in a supernova.
Welcome to the universe. You are made of exploded stars. If there had been no Phase I (metal-poor) stars, there would be no planets, no humans, no nothing, because everything else is made of their exploded corpses.
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You seem a mite bit confused. The article isn't saying that the Earth was created by the mentioned supernova. It saying that this discovery might help us figure out how planets come into being; of which the Earth is one.
That 100,000 year figure has nothing to do with the 4.6 billion year estimate - two different supernovas.
And... Yes, the extant U238 was most likely created by the supernova that created our solar system.
The whole accretion-disk-clumping-into-planets theory has been around for decades, and we've seen signs of accretion discs around stars before. What's new here is that such a disc has been found around the remnants of a star that's already gone supernova -- an event which would have destroyed any previous solar system.
This is the missing link which explains why we've found planets around pulsars, because any planets formed earlier in the star's lifetime would have been destroyed in the supernova.
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A Debris Disk Around An Isolated Young Neutron Star
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This begs the question
No, it doesn't.