This artist's conception depicts an Earth-like planet orbiting an evolved star that has formed a stunning "planetary nebula." Credit: David A. Aguilar (CfA) The search for a planet like our own Earth just got one step closer to the ultimate goal. Astronomers have confirmed three more exoplanets orbiting their stars in the habitable zone — where the temperature is just right for liquid water to exist on a planet’s surface. They also added five worlds that are likely in their stars’ habitable zones. This new crop of planets nearly doubles the number of worlds up to twice Earth’s size in habitable zones. And it includes two of the most Earth-like planets yet discovered.