You folks might want to read up on the Drake equation if you haven't already. Some interesting stuff. I know it's hard to put too much faith in these numbers, but some estimate suggest there are between 1,000 and 100,000,000 civilizations in the galaxy. Pretty cool stuff. I was basically going to post this. If they think there is 17 billion 'earthy' planets and say, 1 in a 1000 are in the "goldilock zone", that's still 17 million planets. Even if the odds of life capable of say, radio communications, are tiny, there are still going to be quite a few of them out there.
