This is a major discovery.
Space.com: Odds of Life on Newfound Earth-Size Planet '100 Percent,' Astronomer Says
An Earth-size planet has been spotted orbiting a nearby star at a distance that would makes it not too hot and not too cold — comfortable enough for life to exist, researchers announced today (Sept. 29).
If confirmed, the exoplanet, named Gliese 581g, would be the first Earth-like world found residing in a star's habitable zone — a region where a planet's temperature could sustain liquid water on its surface.
"It's both an incremental and monumental discovery..."