The larger the volume of space considered, the higher probability there is that a thing exists somewhere in it. Plus, if aliens have landed on earth, you also n

The larger the volume of space considered, the higher probability there is that a thing exists somewhere in it. Plus, if aliens have landed on earth, you also need to postulate a cover-up that has successfully prevented almost everyone from finding out. It's not about sanity, it's just about understanding how much evidence certain claims require to be considered likely.