Ligiaogi, I do not believe in aliens from another world because there is no evidence that they exist. If there are life forms on other worlds in the universe they may not have the capability to travel from one star system to another unless they can travel near the speed of light. If they can't do that visiting another world is futile. The nearest star from here is more than 10 light-years from here. It would take more than 10 years for anything to travel from there to here and if the speed is slower it will take hundreds of years to get here. With that thought in mind it is impossible for unintelligent life form to travel from the nearest galaxy to us because it is 2.5 million light-years from here. It would take any life form more 2.5 million years just to get here.