This program discusses the concept of the expanding Universe. Calculations by astrophysicists show that the cosmos seems to be speeding up. The 50-billion galaxies thought to comprise our Universe are rapidly moving farther apart. As our Sun's energy diminishes, scientists are working to understand the nature of space called "mysterious dark energy and dark matter" - believed to comprise 96 percent of the Universe. With each discovery made by astronomers and astrophysicists, we find there is so much more to learn.