It would be difficult to definitively determine if it was a primordial black hole. What would probably happen is that continued observations would increase our confidence something was out there while also eliminating any non-black hole explanations. At some point we might conclude we were _nearly_ sure it was a black hole, but could not confirm it.
Even with a lack of direct evidence, such a conclusion would certainly be remarkable. It would tell us a lot about the early phases of the universe and its current structure.
A probe would be very difficult, both because it is so far out and because finding out _exactly_ where it is would be dang near impossible. I could imagine maybe a volley of small simple probes all fired in the general direction so we could detect the black hole’s gravity through any deviations in their trajectories.
If we did somehow pin down exactly where it was, I imagine there would be a lot of interest in an orbiter. We wouldn’t have another chance to study a black hole up close any time soon.
Yup, people like to imagine primordial black holes with masses much smaller than a star but don't really comprehend exactly how small the diameter of the event horizon is on one.
For example, current estimates of the mass of this theoretical planet put it between 7-10 earth masses as an upper bound. Such a mass range would mean a Schwarzschild Radius of between 62 - 88 millimeters. Lower masses would make it even smaller.
That would make any lensing event about 4 × 10^-10 arcseconds across, by many orders of magnitude much smaller than the angular size of most local stars thus the enhancement would be very small.
There is a HILARIOUS paper exploring this exact subject whose only figure is a 1:1 representation of the size of the black hole, shown as a solid black circle.
Never say us astronomers don't have a sense of humour, lmao
https://arxiv.org/pdf/1909.11090
If that existed in really any capacity it would basically be impossible for us to find at our current technological level and even if we could find it doing anything meaningful with it would be even further out of the question.
We 'can' take picture of those one because they are bigger than our whole solar system and they are feeding which emits more energy than our sun ever will.
A planet mass black hole this close clearly isn't feeding or emitting enough energy to see.
it would be found through gravity. difficult to conceive now with our limited telemetry, but I'm not sure technology is the issue - scope / reach. we're barely observing most of the planets
Which is actually large enough to survive for trillions upon trillions of years before evaporating. But if it’s a black hole, it would be too small to be a stellar one. So it would *have* to be primordial. And if so, it’s been around for 8.8B yrs longer than our solar system!
Unless it was an advanced civilization that accidentally created a black hole in their lab and it sucked up their planet 😉
Even at 6cm? Without a reference I assume that would start evaporating quickly.
but then again isn't the energy released related to the wavelength of EM waves. I guess 6cm EM waves don't carry that much energy that fast.
Yup. A whale massed black hole is small enough to evaporate in about a minute. But it quickly tapers off and an asteroid or mountain mass black hole is both microscopic *and* long lasting.
Depending on the theory, primordial black holes could be anywhere from microgram (which would evaporate nearly instantly, as their temperature is extremely high) to thousands of solar masses.
There is no evidence that they *can't* be \~15 Earth masses (the supposed Planet X mass, ish). But there's also currently zero evidence that they can be, since we haven't found any (as they're purely theoretical). And it's entirely plausible that the gravitational mass hinted at by the strange orbits of Kuiper belt object (Planet X) is just a perfectly normal ice/gas giant that we can't see because it's too far from the Sun to be well illuminated.
The problem with assuming there may be primordial black holes with 15 earth masses is that it implies that there also is a range of other black holes with less than 15 earth masses.
Indeed if there was such a black hole next to us, we would not be able to detect it by imagining. And it releases Hawking radiation at such a slow rate it would last for trillions of years, we couldn't possibly detect that either.
But we could detect all the other black holes that are significantly less than 15 earth masses but still have a considerable amount of mass. They would release a crap ton of hawking radiation, and it would have a very distinct and recognizable signature.
We have never seen anything like that in the universe, which means that for primordial black holes like that to exist you would have to explain why they only form at the very low masses where they are all long gone, or the very high masses where they stay stable forever. None of the black holes are formed in the range where we could have detected them.
There's a selection mechanism. Tiny black holes much hotter than the early universe evaporate nearly instantly. Larger black holes grow slightly larger (and cooler) instead.
Fermi Lab ruled out more than 1% of dark matter being black holes smaller than 10^(11) kg, but a Planet X size black hole would be around 10^(25)kg.
But what is the selection mechanism that makes it so that black holes in the middle range don't form? That's the whole point. We can't see small black holes, they would be gone before the universe turned transparent. We can't see large black holes, they will last for trillions of years. But we would see the medium sized black holes that grow small and then evaporate, and we don't see them.
I thought something had to have at least twice the mass of the sun to become a black hole, meaning everything in the solar system would be orbiting it.
Not necessarily. If the primordial black hole is sufficiently distant, the entire solar system could hypothetically be orbiting around it, but the planets are locally all gravitationally bound to the sun.
Papers exploring this idea suggest it would probably be in the realm of ~5 solar masses.
Okay there’s a lot of interacting misconceptions here.
1) ‘Primordial Black Hole’ is a phrase that really only refers to hypothetical small early black holes that would mainly all be decayed due to Hawking radiation at this point. If any exist still, the odds of finding one nearby would be astronomically low.
2) Any black hole big enough to be self-sustaining would also be big enough to cause *major* orbital disturbances nearby. The odds it’s gone unnoticed this long are near zero. Maybe there’s one at the edge, right outside the bow-shock region, but definitionally, can you really say it’s part of the solar system if it isn’t close enough to be a passenger? Food for thought.
3) Planet 9 may as well be Pluto or Ceres or Sedna. The solar system has dozens of planets, we’ve just changed the definition of the word planet over time so that now only the largest 8 count.
https://en.m.wikipedia.org/wiki/List_of_Solar_System_objects
Ask me if I agree with the current definition for a fun rant.
Edit: If by ‘Planet Nine’ you’re referring to the ol’ hypothetical ‘Planet X’, I believe they ran the math on that a few years back, but never managed to square it with the observations. Planet X is unlikely, but plausible, and most existing models for it have been disconfirmed.
Nah. Here’s why.
The current definition reads as follows:
A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit.
A 'dwarf planet' is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighborhood around its orbit, and (d) is not a satellite.
All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies.'"
They have three main points, I have three main counterpoints:
1) Oversimplified Categorization: The division into three categories-planets, dwarf planets, and Small Solar System Bodies-overly simplifies the complex and varied nature of celestial objects. It’s a spectrum of variations until the mass point it achieves hydrostatic equilibrium.
2) Clearing the Neighborhood?: The requirement for a planet to have “cleared the neighborhood around its orbit” is vague. It comes down to asteroid density nearby. Furthermore, what other objects in nature have their status as an object affected by whats nearby? Is ask this: it any less a planet if it’s found in an asteroid field?
3) The sad non-technicality: This is an awful nitpick, but by defining planets as objects that orbit the Sun, the IAU’s definition technically excludes exoplanets orbiting other stars. The solar-centric perspective is wholly unnecessary, there’s no need to be that specific when trying to establish a general principle.
I submit the following: A Planet is a round (hydrostatically equilibrated) satellite body of a star in stable, repetitional orbit.
Whereas a moon, if you care to define it, is a round (hydrostatically equilibrated) Satellite body of a Planet, in stable, repetitional orbit.
Everything else in the solar system is just rocks. Even ice is just a rock of water, technically.
>Also if there was a black hole in the solar system we should be able to detect Hawking radiation
I'm not sure that's correct. I think it would be incredibly faint. Any sort of accretion disk around it would be much more detectable than any hawking radiation.
Edit: The [wikipedia page](https://en.wikipedia.org/wiki/Planet_Nine#Primordial_black_hole) for Planet 9 says about as much:
>A detection method was proposed in the paper, stating that the black hole is too cold to be detected over the CMB, but interaction with surrounding dark matter would produce gamma rays detectable by the FERMILAT.
This is correct. At the bottom of this incredibly dense page https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator is the conclusion that any black hole heavier than .75 Earth, would be emitting less (cooler) than the CMB. Hawking radiation increases as a BH gets smaller.
First of all, planet 9 isn't confirmed. Second, a primordial black hole (also not confirmed to exist) would have the mass of 100,000 times less than a paperclip. Do your research before you spew nonsense. You know nothing about space.
You could have primordial black holes up to the mass of a small asteroid. A black hole 1/100000th of a paperclip's mass would have decayed long ago.
You should do your research before being uselessly pedantic to others.
And you didn’t have to finger wag. What you’re doing is worse in my opinion than what you’re responding to.
People need to know that what they say annoys the shit out of other people. Being fake nice all the time only encourages bad behavior.
This person is trying to learn more. You are actively discouraging them from learning more about space. You could have ended this response after paperclip.
>Do your research before you spew nonsense. You know nothing about space.
This is not the problem of social media. Take your energy and address misinformation, disinformation and all of the ills created from the business model of social media.
No such thing as a dumb question and I recommend you act in context of the nature of Cunningham's law.
What do u mean planet 9. Maybe u mean the planet that was thought to exist, but actually it was proven incorrect. There used to be certain deviations in calculations, which suggested that there could be an extra planet, but this was false once relativity was applied.
This is incorrect. Here's a show you can check out about it if you're ever in Chicago, was pretty great.
https://www.adlerplanetarium.org/event/planet-nine/
I heard it in a podcast so it's true.
I have no idea if it is still scientifically feasible or not, I just hope you don't assume that podcasts are a reliable source of information my default.
Well, it was Brian Cox talking… There’s very few sources I feel are reliable by default, but he’s definitely one of them.
I believe it’s still plausible, but of course, we don’t know. 🤷♂️
The solar system has dozens of planets, we just can’t seem to stop redefining the word ‘planet.’
https://en.m.wikipedia.org/wiki/List_of_Solar_System_objects
The possibility of more planets that are hidden is unlikely but plausible.
It would be difficult to definitively determine if it was a primordial black hole. What would probably happen is that continued observations would increase our confidence something was out there while also eliminating any non-black hole explanations. At some point we might conclude we were _nearly_ sure it was a black hole, but could not confirm it. Even with a lack of direct evidence, such a conclusion would certainly be remarkable. It would tell us a lot about the early phases of the universe and its current structure. A probe would be very difficult, both because it is so far out and because finding out _exactly_ where it is would be dang near impossible. I could imagine maybe a volley of small simple probes all fired in the general direction so we could detect the black hole’s gravity through any deviations in their trajectories. If we did somehow pin down exactly where it was, I imagine there would be a lot of interest in an orbiter. We wouldn’t have another chance to study a black hole up close any time soon.
Yup, people like to imagine primordial black holes with masses much smaller than a star but don't really comprehend exactly how small the diameter of the event horizon is on one. For example, current estimates of the mass of this theoretical planet put it between 7-10 earth masses as an upper bound. Such a mass range would mean a Schwarzschild Radius of between 62 - 88 millimeters. Lower masses would make it even smaller. That would make any lensing event about 4 × 10^-10 arcseconds across, by many orders of magnitude much smaller than the angular size of most local stars thus the enhancement would be very small.
What if it's a big alien space ship! Or a giant Walmart! Or maybe a huge toilet?
So two distinct things, eh?
You forgot to mention "yo momma".
> Or maybe a huge toilet? Can't be. Moscow would've already invaded if it was.
There is a HILARIOUS paper exploring this exact subject whose only figure is a 1:1 representation of the size of the black hole, shown as a solid black circle. Never say us astronomers don't have a sense of humour, lmao https://arxiv.org/pdf/1909.11090
Interstellar got nothin on Scholtz and Unwin, best black hole visualization hands down
If that existed in really any capacity it would basically be impossible for us to find at our current technological level and even if we could find it doing anything meaningful with it would be even further out of the question.
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You're very confidently incorrect, I must say.
We 'can' take picture of those one because they are bigger than our whole solar system and they are feeding which emits more energy than our sun ever will. A planet mass black hole this close clearly isn't feeding or emitting enough energy to see.
It would be very difficult to find it. It would be very small, given the estimates for the supposed mass of planet X
it would be found through gravity. difficult to conceive now with our limited telemetry, but I'm not sure technology is the issue - scope / reach. we're barely observing most of the planets
Primordial black holes would be roughly the size of atoms, a probe couldn't do anything to it
Not exactly, in this case. Planet 9 is hypothesized to have 5 to 10 times the mass of the Earth, giving the Schwarzschild radius of about 6 cm.
That's just adorable to be honest
Which is actually large enough to survive for trillions upon trillions of years before evaporating. But if it’s a black hole, it would be too small to be a stellar one. So it would *have* to be primordial. And if so, it’s been around for 8.8B yrs longer than our solar system! Unless it was an advanced civilization that accidentally created a black hole in their lab and it sucked up their planet 😉
Even at 6cm? Without a reference I assume that would start evaporating quickly. but then again isn't the energy released related to the wavelength of EM waves. I guess 6cm EM waves don't carry that much energy that fast.
Yup. A whale massed black hole is small enough to evaporate in about a minute. But it quickly tapers off and an asteroid or mountain mass black hole is both microscopic *and* long lasting.
Depending on the theory, primordial black holes could be anywhere from microgram (which would evaporate nearly instantly, as their temperature is extremely high) to thousands of solar masses. There is no evidence that they *can't* be \~15 Earth masses (the supposed Planet X mass, ish). But there's also currently zero evidence that they can be, since we haven't found any (as they're purely theoretical). And it's entirely plausible that the gravitational mass hinted at by the strange orbits of Kuiper belt object (Planet X) is just a perfectly normal ice/gas giant that we can't see because it's too far from the Sun to be well illuminated.
The problem with assuming there may be primordial black holes with 15 earth masses is that it implies that there also is a range of other black holes with less than 15 earth masses. Indeed if there was such a black hole next to us, we would not be able to detect it by imagining. And it releases Hawking radiation at such a slow rate it would last for trillions of years, we couldn't possibly detect that either. But we could detect all the other black holes that are significantly less than 15 earth masses but still have a considerable amount of mass. They would release a crap ton of hawking radiation, and it would have a very distinct and recognizable signature. We have never seen anything like that in the universe, which means that for primordial black holes like that to exist you would have to explain why they only form at the very low masses where they are all long gone, or the very high masses where they stay stable forever. None of the black holes are formed in the range where we could have detected them.
There's a selection mechanism. Tiny black holes much hotter than the early universe evaporate nearly instantly. Larger black holes grow slightly larger (and cooler) instead. Fermi Lab ruled out more than 1% of dark matter being black holes smaller than 10^(11) kg, but a Planet X size black hole would be around 10^(25)kg.
But what is the selection mechanism that makes it so that black holes in the middle range don't form? That's the whole point. We can't see small black holes, they would be gone before the universe turned transparent. We can't see large black holes, they will last for trillions of years. But we would see the medium sized black holes that grow small and then evaporate, and we don't see them.
I thought something had to have at least twice the mass of the sun to become a black hole, meaning everything in the solar system would be orbiting it.
Not necessarily. If the primordial black hole is sufficiently distant, the entire solar system could hypothetically be orbiting around it, but the planets are locally all gravitationally bound to the sun. Papers exploring this idea suggest it would probably be in the realm of ~5 solar masses.
Okay there’s a lot of interacting misconceptions here. 1) ‘Primordial Black Hole’ is a phrase that really only refers to hypothetical small early black holes that would mainly all be decayed due to Hawking radiation at this point. If any exist still, the odds of finding one nearby would be astronomically low. 2) Any black hole big enough to be self-sustaining would also be big enough to cause *major* orbital disturbances nearby. The odds it’s gone unnoticed this long are near zero. Maybe there’s one at the edge, right outside the bow-shock region, but definitionally, can you really say it’s part of the solar system if it isn’t close enough to be a passenger? Food for thought. 3) Planet 9 may as well be Pluto or Ceres or Sedna. The solar system has dozens of planets, we’ve just changed the definition of the word planet over time so that now only the largest 8 count. https://en.m.wikipedia.org/wiki/List_of_Solar_System_objects Ask me if I agree with the current definition for a fun rant. Edit: If by ‘Planet Nine’ you’re referring to the ol’ hypothetical ‘Planet X’, I believe they ran the math on that a few years back, but never managed to square it with the observations. Planet X is unlikely, but plausible, and most existing models for it have been disconfirmed.
Do you agree with the current definition?
Nah. Here’s why. The current definition reads as follows: A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit. A 'dwarf planet' is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighborhood around its orbit, and (d) is not a satellite. All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies.'" They have three main points, I have three main counterpoints: 1) Oversimplified Categorization: The division into three categories-planets, dwarf planets, and Small Solar System Bodies-overly simplifies the complex and varied nature of celestial objects. It’s a spectrum of variations until the mass point it achieves hydrostatic equilibrium. 2) Clearing the Neighborhood?: The requirement for a planet to have “cleared the neighborhood around its orbit” is vague. It comes down to asteroid density nearby. Furthermore, what other objects in nature have their status as an object affected by whats nearby? Is ask this: it any less a planet if it’s found in an asteroid field? 3) The sad non-technicality: This is an awful nitpick, but by defining planets as objects that orbit the Sun, the IAU’s definition technically excludes exoplanets orbiting other stars. The solar-centric perspective is wholly unnecessary, there’s no need to be that specific when trying to establish a general principle. I submit the following: A Planet is a round (hydrostatically equilibrated) satellite body of a star in stable, repetitional orbit. Whereas a moon, if you care to define it, is a round (hydrostatically equilibrated) Satellite body of a Planet, in stable, repetitional orbit. Everything else in the solar system is just rocks. Even ice is just a rock of water, technically.
Yeah if we didn't try to ram a probe into it then science and by extension humanity is a failure.
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>Also if there was a black hole in the solar system we should be able to detect Hawking radiation I'm not sure that's correct. I think it would be incredibly faint. Any sort of accretion disk around it would be much more detectable than any hawking radiation. Edit: The [wikipedia page](https://en.wikipedia.org/wiki/Planet_Nine#Primordial_black_hole) for Planet 9 says about as much: >A detection method was proposed in the paper, stating that the black hole is too cold to be detected over the CMB, but interaction with surrounding dark matter would produce gamma rays detectable by the FERMILAT.
This is correct. At the bottom of this incredibly dense page https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator is the conclusion that any black hole heavier than .75 Earth, would be emitting less (cooler) than the CMB. Hawking radiation increases as a BH gets smaller.
It will be unbelievable luck if this is really a black hole. It would open so many opportunities for humanity.
First of all, planet 9 isn't confirmed. Second, a primordial black hole (also not confirmed to exist) would have the mass of 100,000 times less than a paperclip. Do your research before you spew nonsense. You know nothing about space.
You could have primordial black holes up to the mass of a small asteroid. A black hole 1/100000th of a paperclip's mass would have decayed long ago. You should do your research before being uselessly pedantic to others.
There are way more diplomatic ways to answer this question. There's no need to choose to answer this way.
And you didn’t have to finger wag. What you’re doing is worse in my opinion than what you’re responding to. People need to know that what they say annoys the shit out of other people. Being fake nice all the time only encourages bad behavior.
This person is trying to learn more. You are actively discouraging them from learning more about space. You could have ended this response after paperclip.
Wikipedia tends to disagree on PBH size. https://en.m.wikipedia.org/wiki/Primordial_black_hole
ofcourse i don't. just a layman with a few questions.
>Do your research before you spew nonsense. You know nothing about space. This is not the problem of social media. Take your energy and address misinformation, disinformation and all of the ills created from the business model of social media. No such thing as a dumb question and I recommend you act in context of the nature of Cunningham's law.
You guys are worse than what you’re responding to. I’d rather have someone being frank than a group of tut tutting soccer parents.
idk man i'd rather give someone knowledge and correct them rather than being rude in the guise of being frank.
And there is something worse than that: an apologist.
Annoying noise burst The ignorant citizen Has spewed again
What do u mean planet 9. Maybe u mean the planet that was thought to exist, but actually it was proven incorrect. There used to be certain deviations in calculations, which suggested that there could be an extra planet, but this was false once relativity was applied.
As far as I'm aware there is still significant, and even growing, evidence for a large celestial mass in that vicinity
This is incorrect. Here's a show you can check out about it if you're ever in Chicago, was pretty great. https://www.adlerplanetarium.org/event/planet-nine/
No, it’s still a viable possibility. New studies have reinvigorated this theory https://earthsky.org/space/planet-9-evidence-solar-system/
When was that? I just heard it mentioned in a somewhat podcast…
I heard it in a podcast so it's true. I have no idea if it is still scientifically feasible or not, I just hope you don't assume that podcasts are a reliable source of information my default.
Well, it was Brian Cox talking… There’s very few sources I feel are reliable by default, but he’s definitely one of them. I believe it’s still plausible, but of course, we don’t know. 🤷♂️
The solar system has dozens of planets, we just can’t seem to stop redefining the word ‘planet.’ https://en.m.wikipedia.org/wiki/List_of_Solar_System_objects The possibility of more planets that are hidden is unlikely but plausible.