[Lion]

whether aliens have visited us or not is irrelevant... if they have got this far i am positive that that they would have the technology to make themselves undetectable to us.... the distances they would have to travel are mind boggling so the technology would be way outside anything we can so far comprehend... there are between 500 billion and 1 trillion galaxies at an estimate with each 1 of these containing between 50 billion and 1 trillion stars (average about 250 billion)... that makes for an immeasurable amount of planets ... it is impossible that this tiny little piece of rock is the only place to have life amongst all that ... so YES aliens DO exist ..(they just live too far away !)