The aliens, if they exist, will certainly powerful enough to destroy humanity's paltry defenses (and our satellites will be first to fall during an alien invasi

The aliens, if they exist, will certainly powerful enough to destroy humanity's paltry defenses (and our satellites will be first to fall during an alien invasion), but you are right, they won't bother negotiating or defeating us, they will simply annihilate humanity (via biological weaponry, perhaps), terraform this beautiful bountiful Earth to suit their needs, and use it as they deem fit. For all of humanity's much vaunted intelligence, we really haven't bothered to unitedly plan for any threats from space, natural or otherwise. If advanced alien beings did visit Earth in the past, they could be easily have become worshipped as Gods by the humans of that time. Earth is such a tiny speck in the vast emptiness of space, that unless galaxy colonising aliens are capable of traveling in spaceships at FTL (faster than light) speeds, it may indeed take them hundreds or thousands or millions of years to pass by Earth again on their next sweep through the Goldilocks planets in their terraforming list in this corner of the Universe.