We can't compare anything on earth to the biggest things known in space. The Cosmic Web may connect objects in the universe with threads of Dark Matter. The Lyman-alpha blob is a bubble like structure containing countless galaxies--perhaps the biggest object in the entire universe. Regions of radio-emitting gas called "radio lobes" could be even bigger. Then there are super galaxy clusters which are hundreds of galaxies merged together due to cosmic collisions. Discover which is the largest planet, star, star cluster, constellation, black hole, volcano, galaxy, explosions, moon, storm, impact crater and "void" in space.

By 2050, lunar settlers could be making oxygen, growing food and finding water in a bustling, self-sustaining settlement. See what life may be like on the Moon. The day before the 40th Anniversary of Apollo 11, NGC presents Living on the Moon. Man has always dreamed of living on the moon, and now a team of NASA scientists is proving that dream could be achieved in our lifetime. We take viewers inside Constellation, the space program's plan to establish a human outpost on the moon by 2020. Take a closer look at the plans underway, from upgraded space suits to housing modules and moon vehicles, and examine the challenges ahead, such as finding water, making oxygen, growing food and protecting residents from deadly radiation. Then, using 3-D animation, we'll visualize how the remarkable outpost will take shape.

Beginning with the separation of the fuzzy thinking and pious fraud of astrology from the careful observations of astronomy, Sagan follows the development of astronomical observation. Beginning with constellations and ceremonial calendars (such as those of the Anasazi), the story moves to the debate between Earth and Sun-centered models: Ptolemy and the geocentric worldview, Copernicus' theory, the data-gathering of Tycho Brahe, and the achievements of Johannes Kepler (Kepler's laws of planetary motion and the first science-fiction novel).