Earth's history is marked by one cosmic disaster after another, forging the path of human evolution. Asteroid and comet collisions, flares from the Sun, mass extinctions, supernova explosions, cosmic ray bombardment. You name it, we've experienced it. It's kind of a miracle we're here at all. Now, experts explore how the Earth has teetered on the verge of destruction.

New discoveries have rewritten the history of our solar system, revealing a complex and violent story that begins with the birth of our Sun from the debris of a massive galactic collision, to its eventual fate as a lone zombie star.
It is a dramatic history of elegant beauty and extreme violence. The inner solar system was like a congested highway. Planets crossing lanes, frequent collisions. There were a lot of planets that could have made it but didn't, and we just happen to be one of the lucky ones that did. The players in our solar system's story are more tangled up than we ever imagined. Without all of these things interplaying, the Earth wouldn't have the stable environment that we have today, and life wouldn't be able to exist.

As summer spreads across our planet, honey bees toil, snow geese breed, tadpoles awaken and lions stalk wildebeest in search of lush grass.
Our planet is solar-powered. But due to the Earth's tilt, it doesn't strike its surface evenly. This solar energy arrives in varying amounts at different times of the year. The huge increase that comes with summer also triggers countless migrations.