You mean the only planets WE'D OBSERVED, don't you?

All the extra-solar planets we've "discovered" since 1997 didn't just magically appear out of nothingness, Chaz, any more than Columbus "discovered" America; they were there the whole time.

It was only the self-delusion of a few religious nutcases, along with the limitations of our technology, that allowed anyone to deny the reality of their existence.

http://www.youtube.com/watch?v=fzP0YA1OELs

Thank you.

The sun and the earth have been around for ~4.5by. The sun is gradually getting hotter, and many scientists believe that in 200 to 400my the sun will be too hot to support life on Earth. So we are literally arriving at the 11th hour. In addition, we are lucky enough to have continents and strong tides, which give organisms a mechanism for colonizing those continents. It's hard to imagine starfaring cultures emerging directly from the oceans- you have no higher order energy sources because you don't have rapid oxidation- though of course a low-tech dolphin-like society is entirely possible.

Looming over all, of course, is the "L" in Drake's equation- the length of time any civilization exists before going extinct or reverting to a low-tech existence. One of the reasons I really, really would love to have scientists detect extra-terrestrial intelligence in my lifetime is that it would prove the "L" doesn't necessarily have to be short.

In the mean time, we must act as if we are the only intelligent life in the galaxy, and nurture the candle of civilization as we take our first tentative steps out into the cosmos. Or as Tsiolkovsky famously put it, ""The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever."