Statistical chance of life on other planets...

In a recent poll conducted for the National Geographic Channel, quite a few Americans believe that there is life on other planets. 60% believe so. Statistically speaking, the chance it doesn't exist would be about as probable as seeing ET walk into your room in the next 4 minutes.
The Drake equation should give an estimate, the chance that there is life out there. The Kardashev scale shows us how technologically advanced these aliens could be. I think the most compelling evidence there is in favour of intelligent life out there is that they have not tried to contact us, sorry Fermi...





