Chapter 21, To The Sky!, Chapter 22, Tiptoeing Through the Milky Way Summary and Analysis

The history of space exploration is short but during this time the threat of humans destroying themselves entirely has become a reality. Sagan then recounts the many ways, including asteroid collisions and nuclear war. It looks like we are at a special point in history; we can wipe ourselves out and travel to the stars. Again, we may be forced to colonize space just to survive ourselves. Some attempts have been made to estimate our precarious human existence is and Sagan reviews them. He ends Chapter 21 arguing that while humans have no special place in the universe, they certainly have the right to colonize lifeless worlds.

In Chapter 22, Sagan notes that many religions have discouraged men from thinking themselves capable of anything. Sagan...