5. Tenth Planet, Twin Primes, Bird Flu

Featured segments include: a possible tenth planet in our solar system, the twin prime conjecture, a possible reappearance of the ivory-billed woodpecker, a look at the bird flu and whether it will move to people, the growing of meat in a laboratory culture, an update on stem cells, the link between hurricanes and global warming, and a profile of cancer researcher Tyler Curiel.