The Egyptians believed the sky to be made of iron. The Babylonians believed it was forged by Marduk from the hardest metal. The Greeks and Romans believed it was made of crystal.
The Hebrew normally translated as "firmament" means something that was beaten or hammered out. The concept shows up in Job and Isaiah as well.
it's clear they're talking about the same thing. it was quite a common idea of the universe in that area at that time: a flat (circular) earth, protected by a solid dome, surrounded by water on all sides, and above.
it's completely dishonest to take this idea, and pretend it somehow connects (generally through poor understanding) to some magical floating cloud layer that would have made earth something like venus. they're not the same thing, and neither is scientifically accurate in the slightest. it's just that one
sounds more plausible than the other, because if there was a solid dome of the heavens... what about all those people who've been in orbit? it's just another attempt to distort the bible and reality so that they match.
What happened to this thing since it appears to have still been around after the flood?
maybe the russians broke it with sputnik.