Malhiem was a rather small moon in orbit around the Covenant colony world Joyous Exultation in the Salia System.

It was completely destroyed when a NOVA Bomb carried by the Sublime Transcendence was activated.[1]

Sources

  1. ^ Halo: Ghosts of Onyx Pg. 245 "The tiny nearby moon Malhiem cracked and shattered into a billion rocky fragments and clouds of dust."