Modifying the English isn't unthinkable. What sounds right in Latin?
Here are some possibilities:
nulla res curans superna -> nothing above [i.e., in the heavens] that cares
nihil nisi stellae supernum -> nothing above but stars
nihil nisi inanitas supernum -> nothing above but the void (or, nothing above but emptiness)
nihilitas inanis superna -> an empty nothingness above (maybe too redundant?)
If anyone can do non-wrong Latin, I could use a translation of the following for HPMOR. The original is supposed to be circa 1200.
No rescuer hath the rescuer.
No Lord hath the champion,
no mother and no father,
only nothingness above.