More New Earths Possible

Astronomers using the Spitzer Telescope have found water vapor on the inner edge of the planetary disks orbiting two stars. Both stars, which are unrelated to each other, are fewer than 500 light years distant. The location of the water vapor is important. It implies that if a small, Earth-like planet formed on the inner edge of either disk, as current models of planetary formation have happening, that world could easily have water.

Couple this finding with a model of the Alpha Centairi system that suggests Alpha Centauri B may have an Earth-like planet orbiting in its habitable zone (reported in this blog), and the likelihood of finding new Earths in other star systems seems to be increasing. Since planet hunters have already found numbers of exoplanets similar to Jupiter and Saturn, perhaps new Earths shouldn't be surprising.

Of course, Earth-like planets lead directly to the question of life in the universe. If Earth-like planets are common, is Earth-like life common? If the nearest such world is only 4.3 light years away, we may have the answer to that question sooner than most scientists ever dared imagine.