Skip to main content
Mysteries of Sleep

Up Next

Nature's Fear Factor

Nature's Fear Factor

Season 47 Episode 9
53:21
Human Nature

Human Nature

Season 47 Episode 11
1:33:41
Can We Cool the Planet?

Can We Cool the Planet?

Season 47 Episode 16
53:31
Beyond the Elements: Reactions

Beyond the Elements: Reactions

Season 47 Episode 17
53:31
Beyond the Elements: Indestructible

Beyond the Elements: Indestructible

Season 47 Episode 18
53:30
NOVA Season 47

Beyond the Elements: Life

Season 47 Episode 19
53:32
Looking for Life on Mars

Looking for Life on Mars

Season 48 Episode 2
53:46
Reef Rescue

Reef Rescue

Season 48 Episode 4
54:06
The Cannabis Question

The Cannabis Question

Season 48 Episode 11
53:36
Particles Unknown

Particles Unknown

Season 48 Episode 12
53:28
Edible Insects

Edible Insects

Season 48 Episode 14
53:28
Alaskan Dinosaurs

Alaskan Dinosaurs

Season 48 Episode 21
53:21
Back to Show
NOVA

Mysteries of Sleep

Season 47 Episode 4

From fruit flies to whales, virtually every animal sleeps. But why? Why do we need to spend nearly a third of our lives in such a defenseless state? Scientists are peering more deeply into the sleeping brain than ever before, discovering just how powerful sleep can be, playing a role in everything from memory retention and emotional regulation to removing waste from our brains.

Watch Preview
Sign up now for inspiring and thought-provoking media delivered straight to your inbox.
Support Provided By
Season
Alaskan Dinosaurs
53:21
Intrepid paleontologists discover that dinosaurs thrived in the Arctic’s cold and dark.
Edible Insects
Unlock with PBS Passport
53:28
Take a tasty look at insect foods that could benefit our health and our warming planet.
Particles Unknown
53:28
Join the hunt for the universe’s most common—yet most elusive and baffling—particle.
The Cannabis Question
53:36
As state-legalized cannabis spreads, NOVA explores its little-known risks and benefits.
Reef Rescue
54:06
Scientists race to help corals adapt to warming oceans through assisted evolution.
Looking for Life on Mars
53:46
NASA launches its most ambitious search yet for traces of ancient life on Mars.
NOVA Season 47
53:32
Discover the fascinating chemistry that makes our world and everything in it—including us.
Beyond the Elements: Indestructible
53:30
Discover the fascinating chemistry that makes our world and everything in it—including us.
Beyond the Elements: Reactions
53:31
Discover the fascinating chemistry that makes our world and everything in it—including us.
Can We Cool the Planet?
53:31
Scientists look to geoengineering and other methods to cool the planet.
Human Nature
Unlock with PBS Passport
1:33:41
We can now edit the human genome with a tool called CRISPR. But how far should we go?
Nature's Fear Factor
53:21
Can bringing predators—and fear—back into an ecosystem help restore its natural balance?
Active loading indicator