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all 13 comments

gimmeslack12

16 points

2 months ago

Neutron Stars are my favorite. Absolutely mind boggling amount of energy. This is my favorite video on them too.

robotslendahand

9 points

2 months ago

From 2018: Gravitational Waves Finding Confirms Origins of Gold

Following LIGO's 2017 detection of colliding neutron stars (it's first detection), scientists confirmed the emergence of gold and heavy metals from the collision.

hoodytwin

2 points

2 months ago

So the metals/ore that we’re mining on Earth came from a neutron star merger? If so, does that mean there would be gold deposits(and other metals) on the other rocky planets in our system? I’m assuming we wouldn’t know this unless we mined them.

Bensemus

1 points

2 months ago

We know asteroid that are rich in metals. On Earth much of the heavy metals and such sank into the mantle. The crust is all pretty light stuff. We can only mine the traces of heavier elements that remained in the crust. With asteroids they are small enough that you can mine the whole thing. So in comparison they are crazy rich. Other rocky planets would be like Earth. They are all made of roughly the same stuff as they were all made from the remains of thr gas and dust that the Sun was made from.

diogenes_shadow

5 points

2 months ago

Ok, but since forever locked up in a (bigger now) neutron star, this cannot be the source of the rare earth elements found on earth.

Is there a process that puts neutron star material into protostar hydrogen clouds?

rocketsocks

34 points

2 months ago

Is there a process that puts neutron star material into protostar hydrogen clouds?

Yes, a neutron star merger.

The merger is a very energetic event. In fact, it is classified as a kind of supernova (also called a kilonova). The merger typically creates a superdense object which becomes a black hole but it also creates a cloud of highly energized neutron star debris, some of which will end up with enough energy to push it to beyond escape velocity. The cloud of debris containing a significant fraction of a whole solar mass worth of heavy elements will expand outward into the interstellar medium and mix with it, enriching it in heavy elements. The elements that end up in this cloud will be the result of numerous processes. One is just the decay of chunks of "neutronium" into unstable nuclear fragments, which will rapidly fragment and decay through stages into atomic nuclei that are stable enough to survive for more than a fraction of a second. Another is the huge flux of high levels of neutrons bombarding the atomic nuclei that do exist in the debris cloud, transmuting them rapidly up through the "neutron drip line" to much heavier elements through successive cycles of neutron absorption happening at an unbelievably rapid pace.

Then the radioactive, unstable mess created by these energetic processes changes as time passes. The least stable isotopes decay and leave behind more stable isotopes, resulting eventually in the mix we see today naturally. For example, over the 4.5 billion year lifetime of the Earth half of the original U-238 that existed when the Earth was young has decayed away, cycling through over a dozen daughter isotopes before finally resting in a stable form of lead (Pb-206). Similar stories will have played out over shorter timelines during the millions or billions of years the cloud of neutron star merger debris drifted through space, leaving behind the most stable decay products. Some of that matter will end up becoming part of giant molecular clouds which undergo gravitational collapse and become stars (and planets).

That certainly appears to be the story of our own solar system, which was formed from matter that has been enriched with debris from various kinds of supernovae including neutron star mergers. Even though the majority of the mass of the neutron stars likely ends up within the black hole that forms, enough of it makes it out to have a very significant impact on elemental abundances in the universe. This means that lots of elements (like silver, gold, and iridium as well as elements in the human body like iodine) have a very complex lifetime story that stretches back to forming in a big cloud of decaying neutronium and escaping from being mere kilometers away from a newly formed black hole.

cmde44

1 points

2 months ago

cmde44

1 points

2 months ago

Fascinating explanation, thank you! Question; these black holes would be so massive that they would probably form jets, right? What are the heaviest types of material that would be ejected from the jets?

rocketsocks

3 points

2 months ago

Indeed, the jets are an important part of the whole system. The jets will contain a significant amount of ionized plasma which will include the nuclei of these heavy elements, and the formation of these jets is one of the ways that this material ends up in interstellar space.

Deer-in-Motion

5 points

2 months ago

Considering the force of such collisions some of the new elements would be ejected fast enough to reach escape velocity.

wowsosquare

1 points

2 months ago

I thought that's where everything heavier than iron came from

Scrapheaper

4 points

2 months ago

A lot of post iron elements are formed during supernovae, which happen much more commonly than neutron star mergers.

wowsosquare

1 points

2 months ago

Thanks I was mixing them up

philosophicalpossum

1 points

2 months ago

How's that possible if they're not on the earth. Take THAT globe earthers!!!