Kepler and the Search for Life in Our Galaxy

There are so many stars in our galaxy that even if planets with complex life (animals and plants) are rare – say one for every billion stars – there could still be dozens here in the Milky Way. But we are just beginning to learn about worlds beyond our solar system, called exoplanets, so we really don't have a good idea of what the chances are for advanced life. That's where NASA's Kepler mission