I posted on this topic before. This updates that with some new information and links to some interesting, new articles.
There are a lot of people in the world who, like me, are fascinated with this topic. Although no one has a real answer for the dilemma, that doesn’t keep us from speculating and writing.
Here are a couple recent articles that if you have an interest in the topic you won’t want to miss:
A Mathematical Twist on the Fermi Paradox This one is a good summary article from Discovery® with lots of links and a couple video interviews. Good overview.
New approach to the Fermi paradox is an article published at Cornell (there’s a PDF version there for download).
The Fermi Paradox: Back with a vengeance is a long, thoughtful blog post byGeorge Dvorsky that I think well worth reading.
Lastly there was recently the announcement of finding the first instance of a medium-sized (5 Earth masses), rocky planet. That’s significant because all the others are big and they’re gas giants more like Jupiter or Neptune than the Earth. The bad news is that Kepler-10b is orbiting close to it’s star and, therefore, really hot. But that’s what we’d expect to find with current methods. A body this small has to be in close to gravitationally affect the star in one common method or, in the other, occult enough of the star create a measurable dip in the light from the star. The latter method is how they found this one and it’s been confirmed with the gravitational method as well so it’s well defined for size and mass.
The methods will get better but right now, Earth-sized planets around near solar-mass stars won’t be found if they’re in the right sort of orbit. But stay tuned, these are exciting times for planet hunters!