有意思。

没有大气层，会有水吗？或者说，在没有大气层的情况下 ，可能会形成水滴吗？

找到一个答案。
In a vacuum chamber, the pressure can be extremely low. So low, in fact, that water can actually boil at room temperature.

So, if you put some water in a high-vacuum chamber you will see it boil. (Then, with all that water vapor around, it won't be a high vacuum anymore!)

https://van.physics.illinois.edu/qa/listing.php?id=1514