<p>In the recently released movie <a href="https://en.wikipedia.org/wiki/Passengers_(2016_film)" rel="nofollow noreferrer">Passengers</a> the ship hits a chunk of rock about the size of a softball that punches through multiple layers of hull and creates a problem.</p>

<p>Assuming that a spaceship is traveling away from Earth at near light speed through interstellar space for a distance of 2 to 10 light years is there a significant probability that it would hit a rock that could do serious damage?</p>

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2016-12-28T20:55:00.170Z
What does this have to do with dark matter?
Phiteros
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2016-12-28T21:19:18.527Z
It's utterly impossible to make any kind of sensible calculation about what probability there is of an unknown fictional spaceship design being damaged by an unknown distribution of rocks in space.  Any random number between 0 and 1 is just as good as any answer we could give.
StephenG - Help Ukraine
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2016-12-28T21:34:51.680Z
@StephenG How do you know what's possible or impossible? Just because you don't know how to make such a calculation doesn't mean it is impossible.
Tyler Durden
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2016-12-28T21:56:50.833Z
@TylerDurden it's impossible because of the number of unknowns in the problem.  We don't know how many rocks there are in interstellar space.  We don't know how large the rock would have to be to cause damage.  We don't know how fast the rocks are moving.  We don't know how large this spaceship is.  We don't know what kind of damage is "serious damage".  And again, what does this have to do with dark matter?
Phiteros
CC BY-SA 3.0
2016-12-28T22:06:36.073Z
Unless the movie had a detailed design schematic of the ship, complete with materials and structural analysis **no one** can make the calculation without **guessing**.  And we've no real basis for estimating the distribution of lumps of rock in space.  Science is not a guessing game.  You need facts to work with.  Data.  You haven't got any.  Here's an estimate : I know of one trip by this design of space ship in this fantasy universe, and that one got damaged, so the probability could be 100% from this limited data.  Happy ?
StephenG - Help Ukraine
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2016-12-28T22:17:22.187Z
@StephenG Making snide remarks is not useful.
Tyler Durden
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2016-12-28T23:28:00.513Z
It shouldn't be too difficult to give an order-of-magnitude estimate, and in astronomy we're often quite happy with that. The size distribution and number density of asteroids is not unknown. The cross section of a spaceship is known. The speed doesn't matter, only the total path length. And once you're outside the Solar System the chance, or risk, of hitting a rock is virtually zero. I'm on a phone now, though, so I won't do it, but I agree with the OP, no need for snide remarks.
pela
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2016-12-28T23:42:05.837Z
@pela Why are there no rocks outside the solar system? I know that gas is supposed to be present as dark matter, but is there proof that there are no rocks?
Tyler Durden
CC BY-SA 3.0
2016-12-28T23:55:18.177Z
@TylerDurden Again, I think that you don't understand what dark matter is.  Is your question specifically about dark matter or about normal, baryonic matter?
Phiteros
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2016-12-28T23:58:28.310Z
@Phiteros I am asking about normal matter which may exist in interstellar voids.
Tyler Durden
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2016-12-28T23:59:04.370Z
@TylerDurden Then that's not dark matter, and the title of the question is very misleading.
Phiteros
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2016-12-29T02:39:16.627Z
Probably a better question for here:   http://space.stackexchange.com/   and it's a good question now that the dark matter has been removed, but as Pela said, I don't think anyone knows.   We don't know how many rocks/pebbles/boulders there are in space.    Off the cuff, I would say the risk is low, even for a 10 year journey, but there would be some risk.  If you weigh the very high cost of travel against a low probability risk it's till worth accounting for.
userLTK
CC BY-SA 3.0
2016-12-29T03:03:39.870Z
This could be rephrased as an astronomy question (on the distribution of matter in interstellar space) but as it concerns space travel, and so is off topic.
James K
CC BY-SA 3.0
2016-12-29T07:42:44.813Z
If travelling relativistically, it is likely to be dust particles that are problematic. See http://astronomy.stackexchange.com/questions/17835/would-a-spaceship-have-to-evade-interstellar-clouds?rq=1 And if you go really fast, then pair production in the hull becomes an issue.
ProfRob
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2016-12-29T07:48:15.537Z
See http://physics.stackexchange.com/questions/195648/whats-the-max-speed-a-man-made-satellite-can-travel-in-space-before-its-circuit/196171#196171
ProfRob
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2016-12-30T07:00:04.290Z
@TylerDurden Rocks (and asteroids and planets) form from pebbles, which in turn form from dust grains. For this to happen, the density must be quite high, and the temperature must be quite low. These conditions aren't met outside stellar systems. So while you can find dusty, interstellar clouds, you won't find "rocky" clouds until you get to the next star. But the chance of coming close enough to a star as you go along a random line of sight is virtually zero (after all, the night sky _is_ black).
pela
<interstellar-travel><space-travel>
Do interstellar rocks pose a threat to interstellar travel?
Tyler Durden
# Do interstellar rocks pose a threat to interstellar travel?

(Asked by: username_0 on 2016-12-28)

In the recently released movie [Passengers](https://en.wikipedia.org/wiki/Passengers_(2016_film)) the ship hits a chunk of rock about the size of a softball that punches through multiple layers of hull and creates a problem.

Assuming that a spaceship is traveling away from Earth at near light speed through interstellar space for a distance of 2 to 10 light years is there a significant probability that it would hit a rock that could do serious damage?

**Tags:** interstellar-travel, space-travel
> **Comments:**
> **username_1**: What does this have to do with dark matter?  
> **username_2**: It's utterly impossible to make any kind of sensible calculation about what probability there is of an unknown fictional spaceship design being damaged by an unknown distribution of rocks in space.  Any random number between 0 and 1 is just as good as any answer we could give.  
> **username_0**: @StephenG How do you know what's possible or impossible? Just because you don't know how to make such a calculation doesn't mean it is impossible.  
> **username_1**: @TylerDurden it's impossible because of the number of unknowns in the problem.  We don't know how many rocks there are in interstellar space.  We don't know how large the rock would have to be to cause damage.  We don't know how fast the rocks are moving.  We don't know how large this spaceship is.  We don't know what kind of damage is "serious damage".  And again, what does this have to do with dark matter?  
> **username_2**: Unless the movie had a detailed design schematic of the ship, complete with materials and structural analysis **no one** can make the calculation without **guessing**.  And we've no real basis for estimating the distribution of lumps of rock in space.  Science is not a guessing game.  You need facts to work with.  Data.  You haven't got any.  Here's an estimate : I know of one trip by this design of space ship in this fantasy universe, and that one got damaged, so the probability could be 100% from this limited data.  Happy ?  
> **username_0**: @StephenG Making snide remarks is not useful.  
> **username_3**: It shouldn't be too difficult to give an order-of-magnitude estimate, and in astronomy we're often quite happy with that. The size distribution and number density of asteroids is not unknown. The cross section of a spaceship is known. The speed doesn't matter, only the total path length. And once you're outside the Solar System the chance, or risk, of hitting a rock is virtually zero. I'm on a phone now, though, so I won't do it, but I agree with the OP, no need for snide remarks.  
> **username_0**: @pela Why are there no rocks outside the solar system? I know that gas is supposed to be present as dark matter, but is there proof that there are no rocks?  
> **username_1**: @TylerDurden Again, I think that you don't understand what dark matter is.  Is your question specifically about dark matter or about normal, baryonic matter?  
> **username_0**: @Phiteros I am asking about normal matter which may exist in interstellar voids.  
> **username_1**: @TylerDurden Then that's not dark matter, and the title of the question is very misleading.  
> **username_4**: Probably a better question for here:   http://space.stackexchange.com/   and it's a good question now that the dark matter has been removed, but as Pela said, I don't think anyone knows.   We don't know how many rocks/pebbles/boulders there are in space.    Off the cuff, I would say the risk is low, even for a 10 year journey, but there would be some risk.  If you weigh the very high cost of travel against a low probability risk it's till worth accounting for.  
> **username_5**: This could be rephrased as an astronomy question (on the distribution of matter in interstellar space) but as it concerns space travel, and so is off topic.  
> **username_6**: If travelling relativistically, it is likely to be dust particles that are problematic. See http://astronomy.stackexchange.com/questions/17835/would-a-spaceship-have-to-evade-interstellar-clouds?rq=1 And if you go really fast, then pair production in the hull becomes an issue.  
> **username_6**: See http://physics.stackexchange.com/questions/195648/whats-the-max-speed-a-man-made-satellite-can-travel-in-space-before-its-circuit/196171#196171  
> **username_3**: @TylerDurden Rocks (and asteroids and planets) form from pebbles, which in turn form from dust grains. For this to happen, the density must be quite high, and the temperature must be quite low. These conditions aren't met outside stellar systems. So while you can find dusty, interstellar clouds, you won't find "rocky" clouds until you get to the next star. But the chance of coming close enough to a star as you go along a random line of sight is virtually zero (after all, the night sky _is_ black).  

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## 0 answers

