If a ship went through an asteroid belt where the asteroids are mostly ice, could the ice in any way transfer onto the ship and give it coatings of ice in various places, or would there be absolutely no reason for the ice to form onto the ship's hull.

Edit Assume the ship is moving less than 5m/s relative to the asteroids and that's its outer hull is the sameness temperature as the space surrounding it. (iirc space is 2 degrees Kelvin).

It's proximity to the asteroids will be however close it needs to be for the ice to transfer to it, it would be helpful if you include this in your answer.

  • $\begingroup$ It depends. Is the ship going at close to light speed? Is it gently grazing the asteroids? What is the surface temperature of the ship's parts that come into contact with the asteroids? $\endgroup$ Feb 1, 2018 at 13:43
  • $\begingroup$ Please, don't chameleon your question. This is considered rude, to say it mildly. You are welcome to ask follow-up questions, of course. $\endgroup$
    – Mołot
    Feb 1, 2018 at 14:12
  • $\begingroup$ @Mołot sorry. I will avoid that in future $\endgroup$ Feb 1, 2018 at 14:37
  • $\begingroup$ If you want ice to build up on it, some cryovolcanism might help (ice volcano) In my mind you need a source of ice particles, you can park next to an ice block in space and there is not much transfer of material, and vacuum is a great insulator, my favorite thermos is vacuum insulated keeps stuff hot for 8+ hours. Heat is not transferred by conduction/convection, in a vacuum. It has to be radiated. $\endgroup$ Feb 2, 2018 at 6:01

2 Answers 2


It depends on temperature. Even in space.

I will shamelessly lift this fine answer from the astronomy stack. If you like it, follow the link and give the original author an upvote.


If you simply stick it in orbit around the Earth, it'll sublimate: the mean surface temperature of something at Earth's distance from the Sun is about 220K, which is solidly in the vapor phase for water in a vacuum, and the solid-vapor transition at that temperature doesn't pass through the liquid phase. On the other hand, if you stick your ice cube out in the Oort Cloud, it'll grow: the mean surface temperature is 40K or below, well into the solid phase, so it'll pick up (or be picked up by) gas and other objects in space.

A comet is a rough approximation to an ice cube. If you think of what happens to a comet at various places, that's about what would happen to your ice cube.

As with the comet so with your space ship. If it is cold, and ambient vapor will glom on and accumulate on your ship. If it is warm your ship will slip through the vapor.


No, unless asteroid belt contains a lot of ice dust or considerable amount of water vapor.

Open space is normally a vacuum, or near vacuum. You can spend a millennium in the vicinity of an asteroid and absorb just a few atoms from it. However, if space is filled with fine dust or vapor (and, as far as we know, this would be very uncommon), you should be able to absorb some of that material. At 5 m/s and 2K this process can proceed without much issues, but if the spaceship would go with a speed that is more normal to spaceships (like 5 km/s), this dust or vapor would present extreme danger to it.


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