Quote from Nyxion
1) Who cares? It's a game.
2) Minecraft clearly isn't on Earth and it's arguable it's even in the same universe. Who's to say what can happen in space there?
3) Why add a new ore? What use could a new ore have, except some goofy new tool tier with silly effects? Toss in a rare ore we already have available. Simplify.
And aliens...No. Seriously? Creepers are fine. Aliens...That's original!
1.people who care about realism.
2.minecraft may not be on earth but is based of earth.
3.adding a new ore to something that can't be found in the overworld normaly would be more fun than just adding one of the same ores that can be found in the overworld.