# Neutron star collision - gold formation **URL:** \ **Category:** Factual Questions\ **Created:** [October 22, 2017, 1:47am UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517 "2017-10-22T01:47:52Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 22, 2017, 1:47am UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/1 "2017-10-22T01:47:52Z")
So as I understand it (very simply put) when two neutron stars collide they create and throw out lots of gold: [https://www.google.com/amp/abcnews.go.com/amp/Technology/wireStory/scientists-witness-huge-cosmic-crash-find-origins-gold-50509163](https://www.google.com/amp/abcnews.go.com/amp/Technology/wireStory/scientists-witness-huge-cosmic-crash-find-origins-gold-50509163) This gold is in dust form (along with lots of other materials) that gravity may one day draw together as a planet, such as earth. My question is, why is earth’s gold in veins? Why aren’t the gold particles just mixed in randomly with all of the other materials that originally formed the earth? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 22, 2017, 1:57am UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/2 "2017-10-22T01:57:06Z")
I don’t know the full answer, but two pieces of it: For one thing, gold is very dense, nearly the densest chemical substance in the Universe (“chemical substance” as opposed to the material of white dwarfs or neutron stars). When the proto-Earth was still molten, the various materials tended to separate out by weight. This naturally put most of the Earth’s gold in the core; it’s only occasionally that volcanic activity brings some to the surface. Also, unlike most metals, gold is extremely unreactive. Most metals are found in the form of oxide ores: It’s only copper, silver, and gold, plus a few even less common than gold, that are found in their pure form. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [October 22, 2017, 2:39am UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/3 "2017-10-22T02:39:58Z")
One current theory is that Gold is dissolved in water, and gets deposited in vies during [earthquakes](https://www.livescience.com/27953-earthquakes-make-gold.html). ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [October 22, 2017, 3:29am UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/4 "2017-10-22T03:29:08Z")
> [@Chronos](#): > > This naturally put most of the Earth’s gold in the core; it’s only occasionally that volcanic activity brings some to the surface. Most volcanoes are very shallow, with all melted rocks coming from lower parts of the crust itself (or maybe the upper mantle) coming nowhere near the core. Possibly all the gold found on the surface today [came from asteroid strikes](https://www.popsci.com/science/article/2011-09/meteorites-gave-us-all-our-extractable-gold-new-study-says). The question of gold in veins can be asked about pretty much any element or mineral found only in specific locations, and the answer is: [it’s complicated](https://en.wikipedia.org/wiki/Ore_genesis). ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [October 22, 2017, 8:44am UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/5 "2017-10-22T08:44:36Z")
I had no idea that gold was mostly made by merging neutron stars. In fighting my own ignorance, I came across this neat [periodic table of elements](https://upload.wikimedia.org/wikipedia/commons/3/31/Nucleosynthesis_periodic_table.svg), color-coded by origin (SVG link). ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [October 22, 2017, 12:12pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/6 "2017-10-22T12:12:22Z")
This is fairly new to me. What I have always understood was the supernovas both produced the heavier-than-iron elements as well as dispersed them into space for later planet formation. Would neutron star collisions be nearly as effective at this as supernovas? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 22, 2017, 12:18pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/7 "2017-10-22T12:18:32Z")
Neutron star collisions _are_ supernovas. Or at least, one kind of them. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 22, 2017, 12:59pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/8 "2017-10-22T12:59:03Z")
> [@Darren\_Garrison](#): > > Possibly all the gold found on the surface today [came from asteroid strikes](https://www.popsci.com/science/article/2011-09/meteorites-gave-us-all-our-extractable-gold-new-study-says). That’s an interesting and compelling article but if true makes the existence of gold veins even more mysterious to my mind. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [October 22, 2017, 1:29pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/9 "2017-10-22T13:29:58Z")
> [@Chronos](#): > > Neutron star collisions _are_ supernovas. Or at least, one kind of them. To expand on this: Since “nova” refers to the appearance of a _new_ visible star, from an observational perspective any transient light source falls into the category. However, I think an astrophysicist would not usually include mergers into the category “supernova”, at least not without qualification. “Kilonova” has been coined for these massive mergers. > **[Kilonova](https://en.wikipedia.org/wiki/Kilonova)** > > A kilonova (also called a macronova) is a transient astronomical event that occurs in a compact binary system when two neutron stars or a neutron star and a black hole merge. These mergers are thought to produce gamma-ray bursts and emit bright electromagnetic radiation, called "kilonovae", due to the radioactive decay of heavy r-process nuclei that are produced and ejected fairly isotropically during the merger process. > The measured high sphericity of the kilonova AT2017gfo at early epo The exis... ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [October 22, 2017, 1:45pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/10 "2017-10-22T13:45:48Z")
> [@Chronos](#): > > Neutron star collisions _are_ supernovas. Or at least, one kind of them. But much rarer. That would imply if the sun formed from a nebula where such a collision never took place, the amount of gold on the planet would be very meager. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [October 22, 2017, 3:44pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/11 "2017-10-22T15:44:44Z")
> [@Lucas\_Jackson](#): > > That’s an interesting and compelling article but if true makes the existence of gold veins even more mysterious to my mind. Oversimplifying it (and I’m no geologist/mineralogist myself) it is chemistry and physics. We get veins of gold for similar reasons that we get frost on windows and pillars of salt in the Dead Sea. Gold exists in a location and condition that allows it to be dissolved, then moves to a new location without the same conditions and precipitates out. The same goes for the quartz it is associated with. Gold veins are essentially especially blingy geodes. ---
**Author:** ![Precambrianmollusc](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/precambrianmollusc/32/63_2.png) [@Precambrianmollusc](https://boards.straightdope.com/u/Precambrianmollusc)\ **Post date:** [October 22, 2017, 3:49pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/12 "2017-10-22T15:49:01Z")
For what it is worth this article popped up on my linkedin feed regarding how gold gets to certain deposits from the magma. > **[Plume-subduction interaction forms large auriferous provinces | Geology Page](https://www.geologypage.com/2017/10/plume-subduction-interaction-forms-large-auriferous-provinces.html)** > > Gold enrichment at the crustal or mantle source has been proposed as a key ingredient in the production of giant gold deposits and districts. However, Its not a hugely non geologist friendly article and a summary appears to be … “Thus, the generation of Au deposits in the crust may result from the conjunction in time and space of three essential factors: an upper mantle or lower crustal source region particularly enriched in Au, a transient remobilisation event and favourable lithospheric-scale plumbing structures.” Whatever that may mean, but the article has some graphics that may help. The article does indicate this is a competing theory to others that are out there. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [October 22, 2017, 7:33pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/13 "2017-10-22T19:33:28Z")
> [@Mijin](#): > > I had no idea that gold was mostly made by merging neutron stars. > In fighting my own ignorance, I came across this neat [periodic table of elements](https://upload.wikimedia.org/wikipedia/commons/3/31/Nucleosynthesis_periodic_table.svg), color-coded by origin (SVG link). WOW!! This is the neatest item I’ve seen in a long time! Nice find!!! ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [October 23, 2017, 2:30pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/14 "2017-10-23T14:30:19Z")
> [@Mijin](#): > > I had no idea that gold was mostly made by merging neutron stars. > In fighting my own ignorance, I came across this neat [periodic table of elements](https://upload.wikimedia.org/wikipedia/commons/3/31/Nucleosynthesis_periodic_table.svg), color-coded by origin (SVG link). Thanks for that link. Very cool! ---
**Author:** ![rbroome](https://avatars.discourse-cdn.com/v4/letter/r/838e76/32.png) [@rbroome](https://boards.straightdope.com/u/rbroome)\ **Post date:** [October 23, 2017, 3:00pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/15 "2017-10-23T15:00:39Z")
> [@Mijin](#): > > I had no idea that gold was mostly made by merging neutron stars. > In fighting my own ignorance, I came across this neat [periodic table of elements](https://upload.wikimedia.org/wikipedia/commons/3/31/Nucleosynthesis_periodic_table.svg), color-coded by origin (SVG link). That is a cool table! I learned about s-Process of element formation in Sixty Symbols and it goes into some detail: It shows how many of the heavy elements are made inside stars including neutron stars. ---
**Author:** ![Hooleehootoo](https://avatars.discourse-cdn.com/v4/letter/h/eada6e/32.png) [@Hooleehootoo](https://boards.straightdope.com/u/Hooleehootoo)\ **Post date:** [October 23, 2017, 5:08pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/16 "2017-10-23T17:08:56Z")
With so many neutrons, one would expect the fissionable elements to be splitting at the same time as other processes are creating Th, U, Pu, right? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 23, 2017, 8:41pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/17 "2017-10-23T20:41:44Z")
With a neutron star collision, pretty much all processes are going on at once. They’re not all going at the same rate, though, so in the end once everything cools down, you’ll have a mix of elements in various proportions. ---
**Author:** ![zimaane](https://avatars.discourse-cdn.com/v4/letter/z/a3d4f5/32.png) [@zimaane](https://boards.straightdope.com/u/zimaane)\ **Post date:** [October 25, 2017, 8:28pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/18 "2017-10-25T20:28:51Z")
If a neutron star is made up of, you know, neutrons, where do the protons in the synthesized gold nuclei come from ? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [October 25, 2017, 8:39pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/19 "2017-10-25T20:39:48Z")
> [@zimaane](#): > > If a neutron star is made up of, you know, neutrons, where do the protons in the synthesized gold nuclei come from ? Free neutrons will naturally decay into a proton, electron, and an electron anitneutrino. Gravity forces the neutrons to remain stable in a neutron star. Disrupt that and lots of energy (the scientific term is “oodles”) is available to break down neutrons and build up just about anything. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [October 25, 2017, 8:42pm UTC](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517/20 "2017-10-25T20:42:18Z")
> [@zimaane](#): > > If a neutron star is made up of, you know, neutrons, where do the protons in the synthesized gold nuclei come from ? From neutrons decaying into protons, electrons, and various other debris once a chunk of the neutron star too small to remain neutronium is chipped off the star. [Next page](https://boards.straightdope.com/t/neutron-star-collision-gold-formation/799517.md?page=2)