You are living in a golden age of discovery.
In its short tenure in Earth-trailing orbit staring unceasingly on the stars in the Cygnus-Lyra region of the Milky Way and looking for the tell tale blink-blink of other worlds momentarily blotting the star light reaching its open aperture, Kepler has expanded to 2,326 the number of candidate planets known to us. Of those, it's believed that 139 may circle their parent suns in orbits compatible with the presence of liquid water.
Over time, ground based scopes will conduct follow up observations to confirm the finds.
Isn't it amazing that in the short period of time that we've been able to detect these new worlds with improved astronomical techniques - a mere dozen years or so - information pointing to their existence now routinely pops up in the data?
Even if we find Earth-like worlds with watery surfaces, what is the real world, practical application of knowing that another planet like ours orbits in the habitable zone of its parent sun? After all, at distances ranging from tens to hundreds of light years away, no one from this period in our history will ever see them at close range. Still, as physicist Brian Cox explains to the BBC in response to the discovery of the most Earth-like of the most recent batch candidates, Kepler 22-b, it's one of the great questions ever. "Are we alone?"
The answer is illuminating either way.
For if we can find life elsewhere, let's say microbial life in the irradiated soil of Mars or beneath the ice of Europa or in the methane seas of Titan, to take three examples, then life may be a common feature of the universe. On the other hand, if we find no evidence of primitive life nearby, or locate terran hosts like ours with instruments like Kepler and, should it be flown, the Hubble successor, the James Web Telescope, would knowing we are alone in this vast and unreachable darkness then change how we behave?
Give the linked audio a listen.
Image Credit for Kepler's field of view: Carter Roberts / Eastbay Astronomical Society.