One cannot.
None whatever.
What does that have to do with you blindly guessing there are none?
But the question is not "IS IT POSSIBLE THERE IS LIFE ON ANY OF THOSE PLANETS?" Of course it is possible.
The question is, "IS THERE LIFE ON ANY OF THOSE PLANETS?"
The only reason you are having so much trouble with this "god" issue, Zen...is because you, like the many theists with whom I discuss this, HAVE ALREADY MADE A BLIND GUESS ON THE ISSUE...AND YOU JUST WILL NOT ACKNOWLEDGE THAT YOUR BLIND GUESS MAY BE WRONG. (Or, like the theists, will not acknowledge that it may be wrong without qualifying in an illogical way, that your blind guess is much more likely than the opposite blind guess.)
It is silly. You are too intelligent not to see that it is silly.
We do not know if any gods exist...and there is no way (at this time/maybe never) to be able to determine if there are any or if there are none. We also are not able (logically, scientifically, or mathematically) to determine which is more likely to be the case.
It really is easy.