Great thoughts,

The word "Vyoma" actually means space more than atmosphere in Sanskrit (I fixed it, good catch). Sanskrit is quite hard to translate as it is extremely context based.

That said, it could have been from an earth's perspective, but if you look at the hymns as it progress, it consistently talks about the overall universe.

Also it is point in Atharva Veda specifically also talks about this creation as when when noting existing in the Universe.

To a good amount of certainty many Scholars as ascribed this to the creation of the Universe (It is also called the Hymn of Creation).

I am not an expert either so please feel free to interpret or probably consult a scholar.