What is Zenith?
The “star” called Zenith, which always remains in the same place on the Sky Dome (instead of tilting and moving clockwise like the rest of the stars), is actually a dwarf observation balloon. The “zenith” referred to was the peak of the trajectory of dwarven missiles aimed at a foe in the First Age. The dwarves in the observation balloon sent launch corrections down to their comrades at high-plateau launch pads.