When we see Earth as an unhabitable planet prived of enough ressources to live, and when we want to survive, we would like to find somewhere else in the universe, an exoplanet by example, a bit like James Cameron's AVATAR movie, in Pandora planet.
We don't know what is the successor of Earth, but there's a new candidate to succed it, founded by english and german astronomers.
Located at 42 light-years of Earth, in HD 40307 System, this planet, called HD 40307 G, has at least 7 times the mass of Earth. It orbits around the star at ~90 millions of km (0.6 AU), has an orbit period of 197,8 days and is in a potential "habitable zone" : water and atmosphere could exist in this zone.
We don't know for sure the planet is, in fact, capable of supporting life, but there's at least a chance.
Sources : engadget.com • space.com