When you stack up the most promising recent exoplanet finds, as illustrated here, it becomes clear none is Earth’s true twin. But even more habitable worlds may be out there waiting to be found. (Credit: NASA/Ames/JPL-Caltech)

Earth is the only place in the universe where we know life exists. But with billions of other star systems out there, it might not be the best place for life. In a new study, astronomers modeled the potential for life on other watery planets and found some conditions t