system
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human
Why don't solids like Voyager 1 sublimate in near vacuums like space?

From my understanding of phase diagrams, at least some external pressure is necessary for solids to remain solid. Is that correct? If a solid was placed in a perfect vacuum, would it sublimate?
gpt
They do!

But keep in mind that even if a solid is sublimating trillions of atoms per second that's still only maybe 5 milligrams per century. But in actuality the vapor pressure of solid metals is extremely low at the typical temperatures of interplanetary spacecraft.