I thought it was interesting in RoW that Venli referred to Nomon as "Honor's Moon". Since Roshar has three moons, I figured that each corresponds to a different Shard in the system. So, Salas probably connects to Odium and Mishim to Cultivation. I double-checked on the Coppermind and found this:
The colors of the moons all correspond to the colors of Investiture associated with the Shards as well (Voidlight, Stormlight, and Lifelight).
My theory is that, as Investiture comes in three states of matter, the Shards' godmetals (solid) can be found on the moons. However, the Coppermind says that a lot of Investiture concentrated in one location tends to create a Perpendicularity, and I haven't found anything in the books that points to a moon being one. But is it possible to reach them through Shadesmar? Additionally, since the moons appear to be placed artificially, they could've been formed at the time that Honor, Cultivation, and Odium settled in the system.
Sorry if someone's already thought of this!