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.

Huge asteroids have smashed into the earth, and turned it into an enveloped fire, uninhabitable to almost all life on the surface. The world will get hit again. It's just a matter of when. So, what should we do as a species? Should we just, like the dinosaurs, look up and die? The reasons the dinosaurs are extinct is they didn't have a space program. We do. We have the capability to perhaps escape the Earth.
Astronaut Chris Hadfield believes the only chance for human survival is to escape from Earth and build a space colony, but there are real barriers.

The extraordinary story of Earth and why it is special and uniquely brimming with life among a largely unknown but harsh cosmic arena. It will be told by eight astronauts from their unique perspective of being away from Earth. In the first episode, Astronaut Chris Hadfield reveals the unlikely and unexpectedly interconnected systems that allow life on our planet to breathe.

Gravity is the most powerful and exacting force in the universe. It is pervasive and penetrating. Gravity binds us together, its reach hangs stars in the sky and its grip crushes light. Gravity holds planets together, and leashes them to their suns. Without gravity, stars, comets, moons, nebulae, and even the Earth itself would not exist. Explore how science and humanity discovered, overcame and utilized gravity. Learn what it takes to propel objects into the heavens, to ride a wave or to ski down a slope. Take a front row seat as an astronaut subjects himself to the weightless wonders of the specially modified aircraft used to train astronauts known as the "Vomit Comet."

This is our home, the earth it's, it's the only place we've got. It is one strange rock because it's ours and we are here and we don't know if any other place in the universe, yet, that can support life. We're very lucky to have it as our home.
Astronauts including the legendary Peggy Whitson, who spent 665 days in space, speak about how their concepts of home have changed since their experience.

In May 2009, NASA astronauts embark on a mission to perform maintenance and repairs to the Hubble Space Telescope. As they go about their tasks, danger and beauty are never far away. The nature of space indicates that even the simplest routine can go fatally awry, while amazing photographs taken by the telescope celebrate the wonder of Earth's celestial surroundings.
An IMAX 3D camera chronicled the effort of 7 astronauts aboard the Space Shuttle Atlantis to repair the Hubble Space Telescope.