So, here's the basic idea, brought to you by the ACME corporation; So, we create a pair of magnets. REALLY big magnets. Put one on a planet, one on a moon. Let's say my example is a green Arid Planet and a purple Forest Moon. The magnet yanks the smaller Forest planet into the Arid planet, and creates a massive blast. Now, the Arid planet has purple dirt, cobblestone, and all that jazz from the purple forest planet. A real mixer of biomes. There'd be a huge ball covering space in one area, with meteors lodged into the forest "chunk", and you could dig through the large chunk into that planet's molten core, spilling the magma from the crushed forest into the surface of the Arid planet. My idea is just that; magnets that force two planets' biomes to collide and crash, removing the smaller planet from travel, and adding a huge area to the larger planet. The idea is for items, but this could probably fit in the planets suggestion section too. Not sure which one is more prominent.
The amount of stuff you'd need to do would be MASSIVE. You'd need to calculate at what time to create the electro-magnet's immense force, calculate the orbit times of the other planet and the rotation of it, so you'd have to match THAT all up. That's just assuming you have enough power. You'd also need a lot of copper and iron. Not only that, but WAY before the impact ever happened, serious crap would happen, gravity would go haywire, mountains torn apart, (not to mention life) to the eventual demise of both planets, into a bigger planet, or a asteroid field. Not only that, but it would take a LONG time for it to actually de-orbit and strike, most likely when the whole war is over and everyone is happy, you go "Oh yeah, that big magnet last year I set up? It may have been still running and now the moon might accidentally crash into us." Basically, this idea wouldn't (probably) really work very well, and would be extremely cost effective. Most people would rather stick to the nukes. Yes, and the sphere wouldn't really "exist" and the arid planet would probably turn into one of those ones that don't belong in a alpha sector at all.
