A Ninth Planet?

[Askold]

Unless a rogue black hole eats up the sun. Or Earth.

One scientist did claim that a black hole flying through Earth wouldn't do much damage as it would go through before it had enough time to swallow much of the planet. Not sure on the math on that since I don't know how we would know how fast Earth and the black hole would be moving, relative to each other.

[Tolpuddle Martyr]

Don't really small black holes have a really short lifespan. Recall reading something about Hawking radiation that I'm not clever enough to understand.

[Art Vandelay]

Black holes aren't cosmic vacuum cleaners, they're subject to gravity and orbital mechanics just like any other celestial body. They only way in which they'll suck up a star or planet is if the black hole passes close enough that the snack in question ends up below the event horizon (functionally speaking, a collision course). Otherwise, it'll just slingshot straight by like anything else.

[RavynousHunter]

Unless a rogue black hole eats up the sun. Or Earth.

One scientist did claim that a black hole flying through Earth wouldn't do much damage as it would go through before it had enough time to swallow much of the planet. Not sure on the math on that since I don't know how we would know how fast Earth and the black hole would be moving, relative to each other.

Nope, we'd have centuries of advanced warning, at least.  Black holes output gigantic amounts of radiation, especially x-rays and gamma rays, which we can detect very easily.  Even if it were traveling at the speed of light, the mass of radiation coming from it would be far ahead of the event horizon, so we'd see it coming a long time before it could do us any appreciable damage.

[Askold]

Unless a rogue black hole eats up the sun. Or Earth.

One scientist did claim that a black hole flying through Earth wouldn't do much damage as it would go through before it had enough time to swallow much of the planet. Not sure on the math on that since I don't know how we would know how fast Earth and the black hole would be moving, relative to each other.

Nope, we'd have centuries of advanced warning, at least.  Black holes output gigantic amounts of radiation, especially x-rays and gamma rays, which we can detect very easily.  Even if it were traveling at the speed of light, the mass of radiation coming from it would be far ahead of the event horizon, so we'd see it coming a long time before it could do us any appreciable damage.

...So we would know what is going to kill us but we wouldn't have a way to prevent it?

[dpareja]

Unless a rogue black hole eats up the sun. Or Earth.

One scientist did claim that a black hole flying through Earth wouldn't do much damage as it would go through before it had enough time to swallow much of the planet. Not sure on the math on that since I don't know how we would know how fast Earth and the black hole would be moving, relative to each other.

Nope, we'd have centuries of advanced warning, at least.  Black holes output gigantic amounts of radiation, especially x-rays and gamma rays, which we can detect very easily.  Even if it were traveling at the speed of light, the mass of radiation coming from it would be far ahead of the event horizon, so we'd see it coming a long time before it could do us any appreciable damage.

...So we would know what is going to kill us but we wouldn't have a way to prevent it?

We'd have centuries to develop ways to prevent (or avoid) it.

[RavynousHunter]

Unless a rogue black hole eats up the sun. Or Earth.

One scientist did claim that a black hole flying through Earth wouldn't do much damage as it would go through before it had enough time to swallow much of the planet. Not sure on the math on that since I don't know how we would know how fast Earth and the black hole would be moving, relative to each other.

Nope, we'd have centuries of advanced warning, at least.  Black holes output gigantic amounts of radiation, especially x-rays and gamma rays, which we can detect very easily.  Even if it were traveling at the speed of light, the mass of radiation coming from it would be far ahead of the event horizon, so we'd see it coming a long time before it could do us any appreciable damage.

...So we would know what is going to kill us but we wouldn't have a way to prevent it?

We'd have centuries to develop ways to prevent (or avoid) it.

Bingolio.  Since we'd see it coming, we'd direct all our efforts to stopping it, and even a single century is a LONG time in the world of science.