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.
This artist's concept illustrates Kepler-47, the first transiting circumbinary system — multiple planets orbiting two suns — 4,900 light-years from Earth, in the constellation Cygnus.