In the sky Vs. Through the sky

Question

I read this sentence in a story. Here the pilot is flying an airship: "Vern was steering the vessel through a cloudless blue sky." What does "through the sky" mean? I have always read in the sky. Why "through" has been used?

Answer 1

The sense this is being used is treating "the sky" as a place. You can get the meaning by substituting other places. In addition, the word "steering" is related to controlling the direction of movement. For a sky vessel it could be direction or altitude.

Walking through a room would mean you are in the room and moving. Standing in the room would mean you are there but not moving through it.

So steering through they sky means the vessel is in the sky and also moving through the sky. Some other verb with in might not have the motion aspect. So floating in the sky would mean only that the vessel is in the sky, but not that it was moving.

Answer 2

The use of "through" implies movement, "in" merely says it is there.

Instead of an airship think of a cloud. It can either be in motion, in which case describing it with "through" is entirely appropriate or it could simply be hanging there in which case "in" would be much more descriptive of the situation.