Quote fromThe size of space of space continuum is infinite, thus everything and anything you can possibly imagine must exist someplace, somewhere. The best part is no matter how large you think you can imagine the size of it all, it is constantly expanding at an exponential rate that is too high for even earths most powerful computers to even begin to calculate.
I think a better question lies not with their existence, but how close they actually are to our minuscule planet. Or maybe they are already here?
Or maybe we ARE the aliens!