From the WGBH Forum Network: "Less than a decade ago, the only planets known to exist were the nine of our solar system. Now, astronomers have found more than 100 worlds around other Milky Way stars. Most are Jupiter-sized, but Earth-sized orbs may be hiding nearby. Learn how scientists succeeded in their quest to find these planets and what they have seen so far, and how we will look for life on these new worlds."