How does whitman’s mention of “the mystical moist night-air” in “when i heard the learn’d astronomer” support the theme of the poem?

The theme of the poem is that it is no good to you if you know everything about something if you cannot enjoy it. This is what Walt Whitman thinks of the astronomer and the quote is important because the astronomer would never describe it as "mystical moist night-air", he would know what physics and chemistry do to cause such air. To the poet however it doesn't matter, for him, the air is magical, and he knows how to feel it and how to enjoy it, and for him it will remain a beautiful mystery.

Writing since he was a writer