Episode 1
Horizon Christmas Special: Hand me my Sword, Humphrey
Episode 2
The Case of the Ancient Astronauts
Episode 3
The Mind's Eye
Episode 4
25 Years in Space
Episode 5
Biology at War: The Mystery of Yellow Rain
Episode 6
Beyond the Moon
Episode 7
Biology at War: A Plague in the Wind
Episode 8
Twenty-First Birthday
Episode 9
Halley's Comet - The Apparition
Episode 10
Halley's Comet - The Encounter
Episode 11
The Diary of Discovery
Episode 12
Making an Honest Fiver
Episode 13
Red Star in Orbit: The Invisible Spaceman
Episode 14
Red Star in Orbit: The Dark Side of the Moon
Episode 15
Red Star in Orbit: The Mission
Episode 16
A Close Encouter of the Second Kind
Episode 17
Hide and Seek in Iraq
Episode 18
The Truth About Sex
Episode 19
Assault on the Male
Episode 20
30th Anniversary - The Far Side
Episode 21
Twice Born
Episode 22
Einstein: The Miracle Year
Episode 23
Einstein: Fame
Episode 24
BSE: The Invisible Enemy
Episode 25
BSE: The Human Experiment
Episode 26
Molecules With Sunglasses (Update)
Episode 27
Ice Mummies: The Ice Maiden
Episode 28
Ice Mummies: A Life in Ice
Episode 29
Ice Mummies: Frozen in Heaven
Episode 30
Computers Don't Bite, Inside the Internet
Episode 31
Antarctica: The Ice Lives
Episode 32
Antarctica: The Ice Forms
Episode 33
Antarctica: The Ice Melts
Episode 34
Crash
Episode 35
Darwin: The Legacy
Episode 36
Longitude
Episode 37
Fat Files: Born to Be Fat
Episode 38
Fat Files: Fixing Fat
Episode 39
Fat Files: Living on Air
Episode 40
Atlantis Uncovered
Episode 41
Atlantis Reborn
Episode 42
Life and Death in the 21st Century: Living Forever
Episode 43
Life and Death in the 21st Century: Future Plagues
Episode 44
Life and Death in the 21st Century: Designer Babies
Episode 45
Inside the Internet
Episode 46
Life on Mars
Episode 47
Destination Mars
Episode 48
What Sank the Kursk?
Episode 49
First Olympians: A Horizon Special
Episode 50
Everest: Doctors in the Death Zone (1)
Episode 51
Everest: Doctors in the Death Zone (2)
Episode 52
Lost Horizons: The Big Bang
Episode 53
How Mad Are You? (1)
Episode 54
How Mad Are You? (2)
Episode 55
40 Years on the Moon
Episode 56
Pandemic: A Horizon Guide
Episode 57
Mars: A Horizon Guide
Episode 58
How Many People Can Live on Planet Earth?
Episode 59
Diet: A Horizon Guide
Episode 60
The End of God? A Horizon Guide to Science and Religion
Episode 61
What Makes Us Clever? A Horizon Guide to Intelligence
Episode 62
Japan Earthquake: A Horizon Special
Episode 63
The Space Shuttle: A Horizon Guide
Episode 64
The End of the World? A Horizon Guide to Armageddon
Episode 65
Carrot or Stick? A Horizon Guide to Raising Kids
Episode 66
Extinct: A Horizon Guide to Dinosaurs
Episode 67
The Hunt for Higgs: A Horizon Special
Episode 68
Woof! A Horizon Guide to Dogs
Episode 69
The Hunt for AI
Episode 70
Stuff: A Horizon Guide to Materials
Episode 71
Blink: A Horizon Guide to the Senses
Episode 72
Immortal? A Horizon Guide to Ageing
Episode 73
Mission to Mars: A Horizon Special
Episode 74
The Final Frontier: A Horizon Guide to the Universe
Episode 75
The Truth About Meteors: A Horizon Special
Episode 76
Mend Me: A Horizon Guide to Transplants
Episode 77
Tomorrow's World: A Horizon Special
Episode 78
What's Killing Our Bees? A Horizon Special
Episode 79
Comet of the Century: A Horizon Special
Episode 80
The £10 Million Challenge
Episode 81
The Transit of Venus: A Horizon Special
Episode 100
The Great British Drought
Episode 101
Festival 77: Horizon 2002
Episode 102
Darwin's Dream
Episode 103
A Killer in the Village - Update
Episode 104
Life Story
Episode 105
Sex: A Horizon Guide
Episode 106
Climate Change: A Horizon Guide
Episode 107
The Mystery of Murder: A Horizon Guide
Episode 108
The Horizon Guide to AI
Episode 109
Tim Peake Special - How to be an Astronaut
Episode 110
Jimmy Carr and the Science of Laughter
Episode 111
Horizon Special: The Vaccine
Episode 112
The Life and Times of El Niño
Episode 113
Impact! A Horizon Guide to Plane Crashes
Episode 114
Impact! A Horizon Guide to Car Crashes
Episode 115
Cat Watch 2014 - A Cat's Eye View
Episode 116
Cat Watch 2014 - The Lion in Your Lap
Episode 117
Cat Watch 2014 - Cat Talk
Episode 118
What's The Right Diet For You? Part 1
Episode 119
What's The Right Diet For You? Part 2
Episode 120
What's The Right Diet For You? Part 3
Episode 121
Journey to the Moon: A Horizon Special
Episode 122
Alastair Campbell: Depression and Me
Episode 123
Ice Station Antarctica: Part One
Episode 124
Ice Station Antarctica: Part Two
Episode 125
Coronavirus Special - Part 1
Episode 126
Coronavirus Special - Part 2
Episode 127
Coronavirus Special - What We Know Now
Episode 128
Horizon Special: The Vaccine
Episode 129
Tim Peake Special: How to Be an Astronaut
