Are We Alone Out There?

In the 1990s, scientists unearthed a striking discovery – there are planets outside of our own solar system. Turns out, many of these planets are in a habitable zone capable of supporting water and oxygen. “The current estimate is about one sextillion habitable planets across the universe,” says Garett Graff, author of UFO: The Inside Story of the US Government’s Search for Alien Life Here – and Out There. Given the huge number of planets and the vastness of the universe itself, it seems likely intelligent life could exist (or may have already come and gone). Graff leads a discussion with Bill Nelson, former administrator of NASA and former congressman, Jackie Faherty, senior research scientist at the American Museum of Natural History, and Paul Sutter, astrophysicist and theoretical cosmology professor at Stonybrook University. This discussion was originally recorded at the 2024 Aspen Ideas Festival.