Any life form from another world arriving would be able to extinguish all form of life any time they wanted. In all our arrogance we would just die and the planet would be theirs to do with as they please. We need to quit explaining aliens from other worlds using our history and the fact that we will shoot and kill anything we do not understand. I am sure they have this figured out if they care.

ha!

The fact that they barely left the atmosphere can tell you how impossible it would be to travel millions of light years. Extraterrestrials have never been and will never arrive on earth.