Theory: Reason for Desolations

[Dr. H]

If you look at the Roshar solar system and the planet in the Arcanum Unbounded, you will see that two of the three moons of Roshar share a tangential colliding orbit. I believe that when the two moons, with shared orbits, near each other and the third moon aligns, the impact on the planet is substantial. This impact could cause the desolations every 4000+ years, ripping the planet apart.

[AndrolGenhald]

Weren't Desolations happening more often before though? I think it's more likely the moons influence the Highstorms and cause the Weeping.

[Spoolofwhool]

The original desolations occurred far more often than every 4000 years. IIRC, it was something like less than 100 desolations total in one millennium.

[Dr. H]

Three orbiting moons with elliptical patterns are more likely to have a variable number of 'interesting' alignments with Roshar and the Sun. You could have 100s of lighter lunar and solar alignments when the moons are close and synchronized, followed by a long calm periods when the moons are separated.

I should edit the title to not say 'reason' and rather say 'catalyst'.

[Dr. H]

Update: I asked Brandon about the three moons at the convention in Boston. He did mention that the moons are in an unstable orbit and that it was intentional (might have implications at some point in the future). But he confirmed that they are not the cause of desolations.