I think the only thing I can contribute to this is I think the flash back on the ship with Sthalmann in civvies took place 10 years prior to the present. 10 years ago is when people witnessed the meteor shower so that's the only thing that can probably be assumed with any kind of certainty.

Catapult may be right that trying to figure out why Stahlmann was where he was and why Y'shtola just happened to be there may not be as important to the story as the other events that unfold.