But scientists are excited by the technical achievement of detecting Earth sized "exoplanets" since it increases the chances of one day finding a potential life-bearing world.

A blue and gray and white sphere sprang into being, a perfect representation of a life-bearing world floating in space.

The bulkheads were invisible beyond the projection of star-specked space and the blue-white shape of a life-bearing world.

And since the four known life-bearing worlds were all seeded by the same primordial source, deep in the galaxy somewhere, it wasn't hard to insert that genome into a Terran yeast cell and convince it to grow.

They barely survive the onslaught of a quarantine system, and decide to sneak onto the life-bearing world all the space-borne Imperial technology and weapons and orbital docks seem to be protecting.

"They're far less common, statistically speaking, than nonlife-bearing or prebiotic worlds, but there are so very many stars, and so very many of them have planets, that the absolute number of life-bearing worlds is quite high."

While life-bearing worlds are numerous," the alien said after a moment, "intelligent life is very rare.

The joint colonization of the second life-bearing world in the Centauran system was accomplished with goodwill and an almost unbelievable absence of territorial discord.

The home of the Comet Empire, it travels through space destroying lifeless planets in its path, and sending out fleets of warships to conquer useful life-bearing worlds.

Prior to 2009, methods for exoplanet detection were not likely to detect life-bearing Earth-like worlds.