Crash Course Big History is back! It turns out, we couldn't tell all of the 13.8 billion years of the history of the universe in 10 Crash Course Episodes. So, Big History host Emily Graslie has returned to add 6 more episodes that look at why the stuff we studied in Big History matter. Today, we're starting with a look at why Cosmic Evolution matters. What exactly does the process of the big bang, the formation of stars, and the birth of planets mean to our lives? Let's find out together.

• John Green
• Hank Green