Meteors can drop random but if you break 3 Shadow Orbs there is an increased chance. 2 meteors fell when i broke Shadow Orbs and 1 fell at random. You can place a heap (50) of meteor thingies to make the Meteor Heads spawn or a 7x7 heap.
Steam: judgementryu. L4D2, COD MW, Killing Floor, Magicka, Sanctum, Global Agenda, Terraria, Fable 3. Pokemon White FC: 4641-8628-9531