In July 1947, some unusual debris was discovered at Roswell Army Air Field in New Mexico. Was this the remains of a crashed military balloon, or something from much, much further away? Has the US government spent the past 75 years hiding proof of alien life from us all? In our series on history’s most well-known conspiracy theories, Dr David Clarke gives Rob Attar the lowdown about the Roswell Incident and considers how it relates to the long history of UFO sightings.

History’s Greatest Conspiracy Theories is produced by the team behind BBC History Magazine. For more fascinating stories from the past, head to HistoryExtra, the home of ‘History’s Greatest’ podcasts. There you can find other feeds including History’s Greatest Cities and HistoryExtra LongReads. Find out more at historyextra.com/podcast. We'd love to know what you think about the podcast, so leave us a review and let us know the topics you think we should be covering. Or, follow us on Facebook, X, Instagram or YouTube to keep in touch. You can listen ad-free to this episode and more by subscribing to HistoryExtra Plus here: https://apple.co/4fgRA1d. This episode was hosted by Rob Attar and produced by Jack Bateman. Learn more about your ad choices. Visit podcastchoices.com/adchoices