believed to be the most habitable place for life. >> so you have on this planet over billions of years, very stable zones where the ecosystem stays the same temperature. you have ecolongitude. if you like hot zones, if you're a creature that evolves to have hot things, you move toward the star side. if you're a polar bear or something that likes cold zones, you move toward the shadow side. you find your zone where you're the most comfortable. it stays like that basically forever. >> see? what'd i tell you? bears. the reason we know about gliese 581g is because of these two scientists and the hard work of their teams, teams supported by the national science foundation and nasa, each funded by you, the taxpayer at home. come up with a better name than gliese 581g. if these astronomers are proven