Season
- Season 0 2009-03-08
- Season 1 2010-04-20
- Season 2 2010-10-28
- Season 3 2011-07-28
- Season 4 2012-02-17
- Season 5 2012-12-21
- Season 6 2013-09-30
- Season 7 2014-01-24
- Season 8 2014-06-13
- Season 9 2014-10-31
- Season 10 2015-07-24
- Season 11 2016-05-06
- Season 12 2017-04-28
- Season 13 2018-04-27
- Season 14 2019-05-31
- Season 15 2020-01-25
- Season 16 2020-11-13
- Season 17 2021-08-06
- Season 18 2022-01-07
- Season 19 2023-01-06
- Season 20 2024-01-05
- Season 21 2025-02-07
Season 21 Episode
- Season 21 The Top Ten Extraordinary Discoveries
- Season 21 The Top Ten Mysterious Monoliths
- Season 21 The Top Ten UFO Crashes
- Season 21 The Top Ten Unexplained Technologies
- Season 21 The Top Ten Secret Projects
- Season 21 The Top Ten Mysterious Mountains
- Season 21 Mysteries of the Aztecs
- Season 21 The Glowing Orb Phenomenon
- Season 21 The Legacy of J. Allen Hynek
- Season 21 The Volcano Factor
- Season 21 The Birdman Mystery
- Season 21 The Abduction Files
- Season 21 The Giants
Ancient Aliens - Season 21 Episode 9 The Legacy of J. Allen Hynek
7.00 42 minutes Dr. J. Allen Hynek is best known as the notorious government UFO debunker who became one of the founding fathers of ufology. Was Dr. Hynek right when he ultimately concluded that there is a non-human intelligence on Earth?
