Argues that, while primitive organisms such as microbes are likely abundant in the universe, advanced life and multicellular organisms are incredibly rare, as they require a myriad of special circumstances to survive.
NASA's Kepler Mission has been spotting many "Earth-like" planets within our galactic neighborhood. But what fraction of these Earth-like planets are really like our planet? The more we learn about Earth's remarkable properties, the rarer our planet seems to be. And with it, the life it hosts.