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.'"

Comments

Re:Does this change what we think the earth's age

[jnaujok]

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.