The sun gives us warmth and light. It is the fuel of life. Without the energy of the sun almost nothing grows, thrives or lives. But the sun was not put there for our benefit. It is not this big jolly ball of nice smiling down on us, wishing us all a good day. It is not our friend. The sun is a monster. A planet killer. And we don't see that side of the sun down here.
But eight astronauts, with over 1,000 days in space between them, can show us how being up there helped them understand the suns bright fury.

Our strange rock itself can also be lethal. We tend to think of Earth as our life support but it's not there to support us at all. It's a place that's violent, that's beautiful, that's crazy, that's intense. Mother Nature is a serial killer. We wouldn't be here without mass suicide and events so devastating it makes the extinction of the dinosaurs looks like a tea party. There have been 5 mass extinctions on the planet and 99.9 percent of all species that have ever lived are gone.
Explore the story of how life on Earth has evolved, becoming lethal for life to thrive.

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.

We sure lucked out with Planet Earth. Blue skies, rolling hills, water everywhere. But our home didn't come like this out of the box. Earth was a real fixer-upper, and it took some seriously hard work to build this paradise. Nearly four billion years of renovation. Some tiny, some huge, to make this house a home. Creatures on Earth don't just live and die. They actually change the world around them.
The story of how for nearly 4 billion years, microbes, plants and animals have emerged and sculpted the planet's surface and atmosphere in the strangest of ways.

What makes us human is the squishy triple-pounder inside our heads. It lets us build skyscrapers, and lift a special few of us into space. We are the only species on this planet that can construct realities in our mind and then go actually build it. The story of how our mind evolved on this one strange rock is one of chance, coincidence and impossible odds.
This episode is an investigation into the mystery of the human brain and the chain of events that produced the anomaly of human intelligence.

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.