(07-01-2015 09:04 PM)Kruciff Wrote:  

(07-01-2015 06:17 PM)NIU007 Wrote:  

(07-01-2015 06:05 PM)ericsrevenge76 Wrote:  

(07-01-2015 06:01 PM)NIU007 Wrote:  I know my dad watched an experiment involving a block of ice in a vacuum (not as good a vacuum as space but as good as they could get it) at somewhat cold temperatures (-200 F or so) and it sublimated so fast the block of ice was lifted off the floor. So apparently the temperatures need to be colder than that.

Here is a really good article on Ice in our solar system. It may answer some of your questions and give you a better overall picture of what is going on out there.

https://solarsystem.nasa.gov/yss/display...Background

Thanks - I just wish they would explain how cold it needs to be for ice to not sublimate right away, assuming it's exposed to the vacuum of space.

Just refer to the triple point graph, it's not really just how cold it is, but the ambient pressure that affects it as well.

Yes, but I'm assuming basically a vacuum, which is what you'd have at the surface of most of the moons in the solar system, and some planets, e.g. the ice in Saturn's rings. Which I'm pretty sure would be less than 1 Pascal and thus not even on the chart. Not that I'm sure I completely understand the chart.