Tyson then moves on to consider if life on other planets could exist . He explains how Project Diana , performed in the 1940s , showed that radio waves are able to travel in space , and that all of humanity 's broadcast signals continue to radiate into space from our planet . Tyson says that projects have since looked for similar signals potentially emanating from other solar systems and that the development and lifespan of extraterrestrial civilizations must be considered for such detection to be realized . According to Tyson , civilizations can be wiped out by cosmic events like supernovae , natural disasters such as the Toba disaster , or even self-destruct through war or other means , making probability estimates difficult . Tyson describes how elliptical galaxies , in which some of the oldest red dwarf stars exist , would offer the best chance of finding established civilizations . He concludes that human intelligence properly applied should allow our species to avoid such disasters and enable us to migrate beyond the Earth before the Sun 's eventual transformation into a red giant
Toba disaster
Toba catastrophe theory
The Immortals (Cosmos: A Spacetime Odyssey)