Up Next
Back to Show
NOVA
These Ancient Stones Helped Track the Seasons
Along the river Gambia in Senegal, there are more than a thousand stone circles. The people who placed these stones would have observed how the locations of sunrise and sunset varied over the year.
Support Provided By
Unlock with PBS Passport
53:31
Who created the Nazca lines and why? New clues to one of the greatest ancient enigmas.
Unlock with PBS Passport
53:32
Meet one of the ocean’s most beautiful and destructive species: Lionfish.
53:47
Psychedelics are unlocking new ways to treat conditions like addiction and depression.
53:30
Is artificial intelligence making policing and courts fairer, or is it increasing bias?
Unlock with PBS Passport
53:43
A team tackles the restoration of iconic Notre Dame Cathedral.
Unlock with PBS Passport
53:31
Can innovative engineering projects save Venice?
53:33
Can innovative drugs and therapies finally end HIV?
53:43
Ancient footprints provide new evidence of humans and extinct giant beasts of the Ice Age.
Unlock with PBS Passport
53:20
How could a single ship cause a major supply chain crisis around the globe?
53:16
Sir David Attenborough explores a site with traces of ancient mammoths and Neanderthals.
53:30
In the Arctic, enormous releases of methane, a potent greenhouse gas, threaten the climate
53:31
Explore great ancient Maya cities and why their inhabitants abandoned them.