Big Stars | How the Universe Works

The sun has been lighting our planet for 4.6 billion years and dominates all life on Earth -- but it's a speck in comparison to the other stars in the universe. | For more How the Universe Works, visit http://science.discovery.com/tv-shows/how-the-universe-works/#mkcpgn=ytsci1 Subscribe to Science Channel! | http://www.youtube.com/subscription_center?add_user=sciencechannel Check out SCI2 for infinitely awesome science videos. Every day. | http://bit.ly/SCI2YT Download the TestTube app! | http://testu.be/1ndmmMq