Black holes are the most enigmatic and exotic objects in the universe. They’re also the most powerful; with gravity so strong it can trap light. And they’re destructive, swallowing entire planets, even giant stars. Anything that falls into them vanishes... gone forever. Now, astrophysicists are realizing that black holes may be essential to how our universe evolved—their influence possibly leading to life on Earth and, ultimately, us.
In this series, astrophysicist and author Janna Levin takes viewers on a journey to the frontiers of black hole science. Along the way, we meet leading astronomers and physicists on the verge of finding new answers to provocative questions about these shadowy monsters: Where do they come from? What’s inside? What happens if you fall into one? And what can they tell us about the nature of space, time, and gravity?

In just half a century, the human population has doubled to 7.4 billion, and during that time, astronaut and satellite photos have been capturing the startling changes on our planet. See how humans have made their mark reshaping the planet in our quest for new sources of food, power, and shelter.
From glimmering new megacities like Shenzhen, China to areas affected by climate change like Mt. Kilimanjaro and Florida, witness Earth's changing look--the spectacular and the shocking--from 250 miles up.

When a mysterious cigar-shaped object is spotted tumbling through our solar system, experts race to uncover it's true nature. The object, nicknamed Oumuamua, meaning 'a messenger that reaches out from the distant past' in Hawaiian, was discovered by the Pan-STARRS 1 telescope in Hawaii. Since its discovery, scientists have been at odds to explain its unusual features and precise origins, with researchers first calling it a comet and then an asteroid before finally deeming it the first of its kind: a new class of 'interstellar objects.'
A recent paper by researchers at the Harvard Smithsonian Center for Astrophysics raises the possibility that the elongated dark-red object, which is 10 times as long as it is wide and travelling at speeds of 196,000 mph, might have an 'artificial origin.' The theory is based on the object's 'excess acceleration,' or its unexpected boost in speed as it travelled through and ultimately out of our solar system.

We are living in a new golden age of exploration. Planet hunters are searching far beyond our solar system and they are actually finding new worlds orbiting other suns. Thousands of these alien worlds have already been found, but this is the story of perhaps the greatest discovery yet, a star 40 light-years away with seven Earth-sized planets: Trappist-1.
This new discovery of seven alien Earth-like planets in a faraway solar system is a major milestone in our hunt for extraterrestrial life, and experts investigate the secrets of Trappist -1's mysterious worlds to reveal if we're truly alone in the universe.

Earth's surface is covered in weird and wonderful patterns. The Australian outback is covered in pale spots, the work of wombats; a clearing in the endless green canopy of the Congo rainforest has been created by an incredible elephant gathering; and the twists and turns of the Amazon make a home for rehabilitated manatees. This is our home, as we've never seen it before.

Quinto sets out to discover whether aliens exist and what evidence we have to prove it. He meets with several who say they have encountered extra-terrestrial life–a man who has been abducted by aliens several times since childhood; a man who claims to have extracted an alien implant; and a woman who shows Zachary what it feels like to be abducted into a spacecraft.
Zachary also meets with the world's leading scientists at SETI in Green Banks, West Virginia. There, utilizing the world's largest telescope, they show him the methods they employ to communicate with potential other-worldly visitors and what this research has taught them about a mysterious radio signal they picked up 3 billion light years away.