What I can tell you—when we’re looking for signs of life on a planet, we use Earth as the template. But our suspicion is, once life starts, it’s really, really persistent. It’s essential for the whole Earth system to maintain a relatively stable condition over millions and millions of years. Suppose you were an alien astrobiologist coming to our solar system looking for liquid water. Credit: ESO / M. Kornmesser / N. RisingerBR: Where is the most likely place for life in the solar system?

Source: Forbes February 20, 2018 22:30 UTC