KEPLER PROBE LAUNCH
Follow the link above for the full details of the Kepler planet-hunting probe, launched yesterday. Its designed to look for Earth-sized planets around other stars. It won't be able to tell if they're life supposrting, only if they're there, their approximate mass, and their orbit around their primary star.
I have little doubt that it will find earth-sized worlds, but the big question everyone is eager to find out is if it finds any in the lifezones around other stars. The lifezone is the distance from a star at which water can exist at liquid temperature.
Its a relatively thin range, even given the wide variety of factors that can affect planet temperature, so the chances of any one star having such a planet are very slim. But with the any thousands out there, who knows? the two most disturbing implications would be on the extreme of the spectrum--if kepler fins a whole lot of lifezone worlds, or if it finds none.
If it finds a large amount, that means that life-bearing worlds are probably abundant in the universe. good in many ways, true, but that also means the galaxy is probably full of potential rivals--rivals who might also have a profound head start on us technologically. If nothing else, the very possibility of that will make our expansion out into space more cautious.
The other extreme, if Kepler finds no lifezone worlds, it will mean almost certainly that life is extremely rare, and that for all practical purposes humankind is utterly alone. While that means a lack of potential rivals, that also means a lack of potential friends and partners. If we stumble, there will be no one else to catch us, or even remember that we were here.
I'm sure kepler will find a median between those two--and of course, even if a planet is found in a lifezone, there's no guarantee that it wil actually harbor life. But still, it makes one think...