Maybe. But it could be thicker. It has to be thick enough to hold back the waters above the firmament, and also to contain the stars, which orbit the earth every 24 hours. The sun, moon, and planets orbit the earth from inside the firmament, naturally, and are probably in a water-free environment. The Good Book is an excellent guide on these matters.
The sun, moon, planets, and stars, I thought, were created on a later day, and in the firmament itself. Not above the firmament, not underneath the firmament, but in the firmament. Ge 1:19 -- and the evening and the morning were the fourth day.