I’m pretty sure there’s another condition as well. Somebody has to be somewhere in or near the region that the meteors spawn in order for the timer to start counting down.

This is why in single player you can play for several hours and still not have any meteors if you’ve never been around that northwest region.

In any event, another possible solution is to give yourself admin privileges and just spawn a couple stacks of star metal ore in your inventory every so often. It feels like cheating, but given the necessity of star metal and the mechanical quirks of actually getting some to spawn in single player, it’s pretty much your only practical option if you for whatever reason don’t want to or can’t use mods.