A planet sculpted from cosmic violence. Earth is a very lucky planet. It has ended up the right size and in the right place. This only happened because of violent cosmic collisions. The crazy thing is, if things had been even slightly different, with more or less collisions, we wouldn't be here. We discover the moments that could have destroyed us, but instead made our planet what it is.

Earth, the great killer. Without the cycle of death and sacrifice, from cellular to planetary, life would not be here. From the deaths of stars, to planetary scale mass extinctions and the sacrifice of individuals for a greater genetic good, this is the story of how life evolved hand in hand with death. Death drives evolution. It's hardwired: from our cells to our landscapes, our colorful living planet is only possible because of it. Death leads to opportunity and biodiversity which ironically ensures life on the planet is never wiped out. It's not enough for our planet to be habitable… it also has to be lethal.

The freak accident behind complex life. All life on earth started as single cell bacteria and stayed like that for 2 billion years. Successfully spreading across the planet. So even if we do find alien life, what are the chances of that life being complex – like us? Vanishingly rare… on our strange rock, it's all down to a freak event, which accidentally happened when one cell ate another to create a kind of cellular power pack: mitochondria. This almost miraculous event transforms earth into a complex interconnected food web based on a competition for food. And at the top of the pyramid sits us humans.

Your brain is an anomaly. We tend to think that once the first life emerged it was inevitable that it would eventually evolve into us. But there is nothing inevitable about consciousness. For over 2 billion years no life on earth possessed a brain. And even today, 90% of life doesn’t have a brain. How life and our strange rock came together to create consciousness is a story of almost impossible and unnecessary coincidences….