One of the world’s greatest ancient enigmas, the Nazca lines are a dense network of criss-crossing lines, geometric shapes, and animal figures etched across 200 square miles of Peruvian desert. Who created them and why? Ever since they were rediscovered in the 1920s, scholars and enthusiasts have raised countless theories about their purpose.

Lionfish–long prized in home aquariums–have invaded the Atlantic, and are now one of the ocean’s most successful invasive species, wreaking havoc in waters across the globe. Join ocean explorer Danni Washington on a journey to find out how they took over, why they’re doing so much damage, and what can be done about it.

Hallucinogenic drugs—popularly called psychedelics—have been used by human societies for thousands of years. Today, scientists are taking a second look at many of these mind-altering substances – both natural and synthetic – and discovering that they can have profoundly positive clinical impacts, helping patients struggling with a range of afflictions from addiction to depression and PTSD.

In police departments and courts across the country, artificial intelligence is being used to help decide who is policed, who gets bail, how offenders should be sentenced, and who gets parole. But is it actually making our law enforcement and court systems fairer and more just? This timely investigation digs into the hidden biases, privacy risks, and design flaws of this controversial technology.

Almost 40 years after the discovery of HIV, could we be on the verge of ending the AIDS epidemic in America? How did scientists tackle one of the most elusive deadly viruses to ever infect humans? Can innovative drugs bring new infections to zero?

NOVA presents the dramatic story of NASA’s James Webb Space Telescope and the quest to peer deeper back in time than ever before in the hope of answering some of astronomy’s biggest questions.

Can new emission-free electric planes replace our polluting airliners and revolutionize personal transportation in our cities?

In NOVA's two-part program Dinosaur Apocalypse. Sir David Attenborough explores how a North Dakota fossil dig site could reveal a detailed picture of the day an asteroid struck Earth and wiped out the dinosaurs. But can the remains be linked to that impact event?

Follow three women at risk of developing Alzheimer’s as they join a groundbreaking study to try to prevent the disease – sharing their ups and downs, anxiously watching for symptoms, and hoping they can make a difference.

Some 30 million Americans have sent their DNA to be analyzed by companies like 23andMe and AncestryDNA. But what happens once the sample is in the hands of testing companies? This program explores the power of genetic data to reveal family connections, ancestry, health risks and even solve criminal cold cases.