This is primarily location-dependent, so if one fails to open, moving to a different angle before trying again will increase the chances of the next attempt succeeding. You will see them trail across the sky and hear their explosive boom as they crash on the mountain ridges. Cimmerians nearby hint at this, as they use star metal weapons.
Star Metal Ore can be harvested from meteorites, which will fall in the western region of the Snow biome, just north of the Mounds of the Dead. Put it to your ear and it practically hums with cosmic secrets like the ocean in a seashell. This ore, fallen from the sky, is a gift from the firmament. Who ever saw metal like it in a sane world? It seems less destructible than Aquilonian steel, yet see how it is corroded and eaten away in spots. This is a grisly thing,' shuddered the clerk.