Stars

Immense mirrors built by Quata in an attempt to see and comprehend all that he was. This effort failed and he exploded, his corpse becoming the sun. Much later, The Twelve Gods moved the mirrors to the crystal sphere and attached them there, to help illuminate the farther-flung planets by gathering and reflecting his light. The stars are extremely bright and hot, preventing any creatures from traveling or living there save those made of fire or light.