In a recent public hearing, three government officials told Congress that not only are “unidentified anomalous phenomena” real, they’re a major national security concern. But one witness took his testimony even further, claiming the government possesses materials of “non-human origin.” How much do we really know about UAPs – or, as they’re more commonly known, UFOs? And now that Congress is involved, are we about to learn a whole lot more?  Guest: Garrett Graff, contributor at WIRED magazine; author of the forthcoming book, “UFO: The Inside Story of the US Government's Search for Alien Life Here—and Out There” If you enjoy this show, please consider signing up for Slate Plus. Slate Plus members get benefits like zero ads on any Slate podcast, bonus episodes of shows like Slow Burn and Amicus—and you’ll be supporting the work we do here on What Next. Sign up now at slate.com/whatnextplus to help support our work. Podcast production by Elena Schwartz, Paige Osburn, Anna Phillips, Madeline Ducharme and Rob Gunther. Learn more about your ad choices. Visit megaphone.fm/adchoices