Fetching details from the dictionary...
sky; air; ether; firmament; the heavens
天空に星が輝いていた。
Stars were shining in the sky.
天空を舞う鷹の姿に見入った。
I was captivated by the sight of a hawk soaring through the sky.
古代の人々は天空に神々の意志を読み取ろうとした。
Ancient peoples tried to read the will of the gods in the sky.