Season 1

01 Alien Planets: Anyone Home? Episode 120th February 2002 02 Hubble's Heritage Episode 420th March 2002 03 Extreme Astronomy Episode 53rd April 2002 04 21st Century Cosmos Episode 610th April 2002 Our perception of the universe has changed dramatically from thoughts of a starry, unknown realm to knowledge of the countless galaxies that surround us, yet the scale of the cosmos remains a mystery. How old is the universe? How much matter and energy does the universe contain? 21st Century Cosmos probes questions of cosmology with international astronomers to refine our understanding of how stars and galaxies are formed, if the universe is flat or curved, and how and why the universe will continue to expand.