Imagine if you were an alien species intent on conquering the earth by force. Now, you might just appear over the various capital cities of the world and wait for your countdown to get to zero or you might, being a little timid of the explosive force that you are about to unleash, wish to do it from a safe distance. What you would need to look for, then, is a handy bull's-eye – on the bull's-eye that is the Earth itself.
Look no further, alien invader. The Richat Structure in Mauritania provides the perfect target towards which you can aim your death ray, annihilation laser or whatever you call your extraterrestrial weapon of mass destruction. It’s almost as if another species, in a previous visit, had chalked in a target already and then become bored and wandered back to Betelgeuse.
