CARL SAGAN: The Possibility of Life in the Universe

This lecture by Carl Sagan was delivered in 1979 to a packed university auditorium in Colorado Springs, Colorado. It reflects the science of that time, and in the Q&A Dr. Sagan addresses the related claim that not only is there definitive proof for the existence of Extra-Terrestrial Intelligence in the cosmos, ETIs have visited Earth. Dr. Sagan’s exquisite deconstruction of such claims is a classic exercise in skeptical and critical thinking.