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 1 The Top Ten Extraordinary Discoveries
7.00 42 minutes Ancient Aliens is counting down ten of history's most astonishing discoveries; breakthroughs that challenge traditional beliefs about human history. From a lost city hidden in the Andes, to mysterious metal spheres that are not of this world and a sunken city that was said to be the home of the gods. Could these discoveries provide proof of extraterrestrial contact?
