I'm beta reading a story (no one from here) in which there's a interdimensional rift that this guy goes through because he's getting a hundred grand, and then they threaten to kill his girl if he doesn't so he ends of on another planet and there's a war and alkdfjalskjffffffffffffffffffffffffffffffffffffffffffffff Sorry, fell asleep there. The point of this post is that around this other world there is moon with water oceans. The moon is larger then earth's but I'm pretty sure it's too small to have an atmosphere. So (if I understand my science correctly) the sun should turn those oceans into steam in a matter of hours (the surface temperature of the moon in the sun is 123 C). Then all the steam wouldn't have an atmosphere to hold it so I'm pretty sure it would just stream off into space, but that's where my science isn't entirely sure what would happen. I'd like to be able to tell this guy all of the reasons he's wrong, so if anyone know what else would happen, or other reasons it's impossible go for it.
Io and Europa have atmospheres. Europa has an ocean and an oxygen atmosphere. It all depends on the planets the moon orbits, how far both are from the sun star, the kind of star such as brown dwarf or Sun like star. Orbits and rotation can matter. Whether or not the moon has a molten core or not, and on and on. There are many variables to play around with.
But the average temperatures for both is so low it's measured in Kelvin, their oceans are ice, and Europa has an atmosphere too thin for a plane to fly. So unless this other planet is out past the asteroid belt I'm gonna stick with the first part of my answer.
I agree with GingerCoffee, in fiction there can be settings that might be outlandish to a science enthusiast but plausible enough for a reader. Some of the most successful SF have been against outlandish back-drops (Niven's Ringworld, for example, not to mention some of the places in Star Trek). Judging by the opening lines of your post, you appear to be bored with the book. If that's the case, I think you should say why without entering into an argument with the writer about the plausibility of the moon having water, as there appear to be more important reasons as to why the book isn't working for you. Just my opinion, but I'd want that honesty as the writer, more than scientific arguments.
