
Saving Hubble - Two teams of spacewalkers take on the risky mission of reviving the ailing Space Telescope. First Primates - Our most distant primate ancestors, which lived about 55 million years ago, were tree-dwellers the size of mice. Profile: Alfredo Quiñones-Hinojosa - He jumped the fence from Mexico to work as a farmhand and ended up a leading brain surgeon. Killer Microbe - A relatively benign bug becomes a highly lethal pathogen, known to U.S. soldiers as Iraqibacter.
Dark Matter - Turns out most of the universe is held together by a mysterious, invisible substance. Of Mice and Memory - Mice placed in enriched environments can recover lost memories, giving hope to those who study Alzheimer's. Profile: Hany Farid - This self-proclaimed "accidental scientist" is a digital detective inventing new ways to tell if photos have been faked. Wisdom of the Crowds - Ask enough people to estimate something, and their combined guesses will get you surprisingly close to the right answer.