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Earth is presently facing no threat because no black hole is close enough to the solar system to threaten our planet. We think. According to NASA, even if a black hole with the same mass as the sun replace the sun, Earth still would not fall in.

But could a black hole ever destroy Earth?

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    $\begingroup$ Earth was never alive and cannot be „killed“, it could only be destroyed $\endgroup$ Commented Dec 14, 2022 at 15:46
  • $\begingroup$ A black hole floating leisurely by the solar system would be no threat. A black hole speeding through the solar system would be another story. $\endgroup$
    – Woody
    Commented Dec 15, 2022 at 2:27
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    $\begingroup$ @Woody, How would a black hole "float leisurely by?" How far away is "by?" Any passing BH is going to do a hyperbolic dance with the Sun. If their approach is close enough to perturb the orbits of planets within the Solar System, then we may have a problem. $\endgroup$ Commented Dec 16, 2022 at 20:03
  • $\begingroup$ If a suspected rogue black hole 5000 light years from Earth moving at 45 kilometers per second could magically aim right for us, we could be hit by the pitch and get a free walk to first base in about 33 million years. $\endgroup$
    – Wyck
    Commented Dec 19, 2022 at 16:33

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Answer: YES

Check out Primordial Black Holes https://en.wikipedia.org/wiki/Primordial_black_hole

These Bad Boys formed in the first second after the Big Bang. Unlike the familiar Stellar Black Holes, they could have formed from almost any size mass: from a fraction of a gram to thousands of solar masses. The little ones (smaller than a moderate sized asteroid) would have evaporated by now due to Hawking Radiation.

Primordial Black Holes have been invoked to explain all sorts of mysteries in cosmology, like Dark Matter.

In September 2019, a report by James Unwin and Jakub Scholtz proposed the possibility of a primordial black hole (PBH) with mass 5–15 MEarth (Earth masses), about the diameter of a tennis ball, existing in the extended Kuiper Belt to explain the orbital anomalies that are theorized to be the result of a 9th planet in the solar system.

Are tennis ball sized black holes, many times the mass of Earth, zipping around interstellar space? If one happened to pass through the Earth, we wouldn’t see it coming. It would be “lights out” for everyone.

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    $\begingroup$ @user253751 A tennis-ball sized black hole would pull in quite a bit of matter as it passed through. As a rough approximation it would suck in as much material as could flow through it's surface at the local speed of sound. (And note that the speed of sound in rock is a lot higher than in air.) More important, though, is that we would pass within it's Roche limit--while I don't think the planet would be completely destroyed due to the speed of the passage it certainly would do severe damage. I would not expect life in any form to survive. $\endgroup$ Commented Dec 15, 2022 at 15:58
  • $\begingroup$ @LorenPechtel ... The key is not the size of the event horizon, but the mass. If it is "many Earth masses", it will fragment Earth, not punch a hole. For an interesting read on the topic, "Seveneves" is a great SF book. $\endgroup$
    – Woody
    Commented Dec 15, 2022 at 16:03
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    $\begingroup$ @Woody At low speed it certainly would fragment the Earth. I'm not sure it would shred it if it came in fast enough. $\endgroup$ Commented Dec 15, 2022 at 16:10
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    $\begingroup$ You make it sound like the existence of primordial black holes is well-established science. That's not the case, they are still quite hypothetical, as the linked WP article mentions. $\endgroup$
    – PM 2Ring
    Commented Dec 18, 2022 at 15:03
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It might be best in this case to think of a black hole like any other massive object. Black holes aren't cosmic vacuum cleaners - they obey the same rules of gravity as any other object.

If the sun were replaced by a different star of the same mass, then the Earth would keep going round in its orbit - same mass means same gravity. If the sun were replaced by an improbably large rock with the same mass then it would be the same story (ignoring volume concerns with density), and the same is true with a black hole. The gravitational force on the Earth wouldn't change all that much.

As The Rocket Fan correctly points out, there would be no sunlight and a bit more radiation coming at us, but with all else being equal, the fact that it's a black hole rather than a star doesn't change the rules or make it so we will be sucked in.

If a black hole (of sufficient size) did collide towards us on Earth, we'd be in a fair bit of trouble and probably wouldn't survive. But the odds of that happening are spectacularly slim so I wouldn't worry too much about it.

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    $\begingroup$ If you replaced the sun with an improbably large rock of the same mass I think the results for Earth would be cataclysmic--said rock would promptly collapse into a white dwarf and I can't believe the energy release from doing so would not do very bad things to us. $\endgroup$ Commented Dec 15, 2022 at 16:00
  • $\begingroup$ @LorenPechtel Probably. FWIW, I have an answer about fusion of highly rocky bodies here: physics.stackexchange.com/a/589111/123208 But that answer assumes the giant rock has a lot of heat of formation, due to large amounts of rock colliding from a great height, and that the rock was accompanied by some hydrogen & helium, since that stuff's ubiquitous. $\endgroup$
    – PM 2Ring
    Commented Dec 18, 2022 at 16:31
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    $\begingroup$ @PM2Ring I wasn't talking about fusion. Rather, I was saying that if you replaced the sun with a solar mass worth of rock it would immediately collapse with a spectacular energy release as it happened. The answer you are linking to discusses a fusion burn in the collapsed rock. The reality is you can't have a solar mass of rock sitting around without it becoming degenerate. $\endgroup$ Commented Dec 19, 2022 at 3:50
  • $\begingroup$ @Loren Sure, you can't make a solar mass of rock and expect it to behave like a small piece of rock. I know you were talking about degeneracy, but I figured that the fusion discussion might be of interest to you or to other readers. $\endgroup$
    – PM 2Ring
    Commented Dec 19, 2022 at 9:26
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It depends where it is and where Earth is going. As you mentioned if the sun turned into a blackhole it would not destroy Earth because it would have the same gravitational pull since the mass hasn’t changed and Earth would maintain its orbit. However, the radiation emitted from it would increase. I do not know the exact numbers, but I suspect that it could be a deadly amount which would reach Earth. That wouldn’t destroy Earth, but it could possibly destroy the human race.

If Earth were on a collision course with the blackhole or even got too close, the blackhole could destroy Earth. The closer it gets to the Event horizon the more it would pull on Earth. Earth would then start to get stretched. As it gets closer it will be stretched so much that it would become like a long, thin noodle. This would happen before you cross the event horizon. If you crossed the event horizon all hope is lost and not even light will be able to escape. Earth would also be destroyed.

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  • $\begingroup$ The black hole would be too small to swallow Earth whole. Only some of our planet would be eaten up; the rest would merely be strerced, squeezed, and scrambled, with some of its mass ultimately converted to radiant energy. $\endgroup$ Commented Dec 15, 2022 at 0:58
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Maybe.

As Woody mentions, there might be primordial BHs (black holes), with a wide range of masses, scattered through the cosmos. However, there is currently no observational evidence that they definitely exist, although very small primordial BHs might contribute to dark matter, and primordial BHs of all sizes might have been involved in the formation of the supermassive BHs found at the cores of most galaxies.

Stellar mass BHs are usually formed in core-collapse supernova explosions, when the core of a very massive star collapses at the end of its life. The explosion throws off a lot of matter at very high speed, and the remaining matter forms a neutron star or a black hole. If the star is not quite massive enough, it may collapse to a neutron star or BH without an accompanying explosion.

A supernova explosion is very energetic, and generally not very symmetrical, so the remnant neutron star or BH may receive a substantial kick, causing it to travel at a speed that's considerably higher than the other stars in its stellar neighbourhood. This is known as a pulsar kick.

It is generally accepted today that the average pulsar kick ranges from 200–500 km/s. However, some pulsars have a much greater velocity. For example, the hypervelocity star B1508+55 has been reported to have a speed of 1100 km/s

And from Stellar kinematics

The neutron star RX J0822-4300 [...] was measured to move at a record speed of over 1,500 km/s (0.5% of the speed of light) 

Black holes can have similar speeds, but we have less data about them since they are so hard to detect, unless they are accreting matter, or have a visible companion.

So there could be hundreds or even thousands of high speed neutron stars and BHs travelling through the galaxy. However, as the saying goes, space is really big, and the odds of them colliding with another star system are quite small. And it's quite likely that their natal kick was in some random direction, sending them out of the galactic plane, where they're even less likely to encounter another star.

The smallest black holes formed via core collapse have a mass just under 3 solar masses, neutron stars range from about 1.4 to 2.4 solar masses. If such an object passed through the inner Solar System it could certainly disturb the orbits of the planets, even if it didn't actually collide with anything. A body moving at 1500 km/s could cross from one side of Neptune's orbit to the opposite side in around two months. Even if it didn't cause a major disruption to any orbits it would still modify the dynamics of the Solar System to some extent, affecting the eccentricity and inclination of the planet's orbits, and it could take a long time for the orbits to recover.

Note that if we somehow detected such a rogue BH or neutron star in our stellar neighbourhood at a distance of 10 light-years (roughly the distance to Sirius), moving at 1500 km/s, heading for our Solar System, it would take around 2000 years for it to get here.

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