Seven steps to a HABITABLE PLANET
hich properties are essential for the origin and continued existence of life? And how did Earth acquire them? At a recent online astrobiology conference*, planetary scientist Alessandro Morbidelli (Nice Observatory, France) listed seven key features that could guide astronomers searching for inhabited extrasolar planets. Surprisingly, the slow, protracted growth of Earth, the interaction between Jupiter and Saturn, and the giant impact that formed our Moon may have been decisive factors in making a world that is hospitable to living beings.
