1st August 2010, 8:05 AM
By your logic, if were only assuming life can exist on a planet exactly like ours, then does there need to be 8 planets in it's system? Does it need to have one Moon? I wholly understand the logic of where they are looking but Earth-sized planets have just as much chance to be barren and worthless (See: Mars), and smaller bodies can have much higher chance of forming life (See: Europa).
The Earthworker Race has ended. Everybody wins.